I think that mentality comes not only from having big game players but from their adaptability as a team. While Pep's Barca had a plan A that was enough to outplay any opponent, Zidane's Madrid were different. If a certain plan wasn't working they knew they could change things up easily. They could control the midfield for large periods of the game in similar fashion to Pep's Barca at times but they also could sit deep, play on the counter, they could win games through set pieces, attack through the middle or through the flanks, they were better physically... they were much more complete as a team.
You're not giving Zidane the credit he deserves, his plan A didn't involve anything special tactically but his ability to adjust their way of playing midway through those CL matches was incredible and deserves a lot of praise.
Real was a more versatile team. Barcelona, specially Pep, was devoted to not only winning, but winning with a philosophy that the players had to follow like a religion. That's why Guardiola got rid of Eto'o (Barcelona's top striker in the 2008-2009 season), who did not fully accept Guardiola's philosophy, and this remains the biggest mistake of Pep's career. It might have been the difference between Barcelona not winning the UCL in 2010 and they winning it. Ibrahimovic was a great player, but his individualistic play style weakened Barcelona's traditional plan A. Ibra should not have started the games against Inter, he should only be brought in the end. As Michael Cox said: Guardiola used what should be his plan B as his plan A against Inter. He should first have tired Inter's defense with quick wingers and then in the final stages of the matches bring Ibrahimovic. Guardiola did the opposite.
Coming back to the main subject, Barcelona was so specialized and precise in their passing combinations and precision in tight spaces that they took the whole sport to a newer, higher technical level than ever. Their technical level still remains unmatched and will be unmatched for a long time. I mean, watch these two full games below, this is the best football I have ever seen.
And it's not like Barcelona couldn't or didn't have the players and technical quality to slightly switch their possession play to a more direct and vertical one, they were just too stubborn to do this most of the time. Watch the full match below, in which Barcelona did not really play much tiki-taka. A great performance.
Zidane's Real was great and a jack of all trades, but they never came close to reach these heights. It can be argued that other teams from the 2010s, like Bayern 2012-2016 and Barcelona 2015, or even Real 2012, could reach technical heights of precision, speed, dominance and control similar or better than even Real 2017, which was by far the most dominant Real team coached by Zidane, they were truly great in 2017.
To be fair it wasn't only Ramos..
In the 15 Clasicos that Pep managed, Madrid saw 8 red cards. Ramos only got 2 of those
Real Madrid really was violent and hot-headed against Barcelona in that time. Understandable considering how Barcelona had defeated Real five times in a row. The situation reached a boiling point in the series of 4 Clásicos in two weeks in 2011 in which Real just wanted to stop Barcelona at all costs, including kicking Barcelona's players, Mourinho's trash talking to belittle Barcelona's achievements, letting the grass at the Bernabéu be taller than ideal to hinder Barcelona's passing game and also parking the bus, with Mourinho having three holding midfielders and PEPE as his DM!
Only a simpleton would compare a CL or even a Liga title to a Cup.
You can bet that Pep would swap every other mickey mouse trophy of his for another CL.
You are making it seem as if Barcelona was not extremely winner during Pep's reign. 2 UCLs is truly great! Overall, they won 14 out of 18 official titles in Pep's four seasons. And Barcelona only lost four games in the 2009-2010 season, they were still clearly the best team in Europe despite not winning the UCL. And the 2011-2012 season was an end of cycle, the team was being bad in away games at La Liga and seemed to lose focus, though still a great team that was defeated by Real only once in that reason, beat Real at the Bernabéu two times and reached the UCL semi-finals, being eliminated by a freakishly lucky Chelsea that defeated a great and far superior Bayern team in the final in similar freakish luck fashion. Overall, there is not much difference between Pep's Barcelona and Zidane's Madrid when it comes to winning titles, both squads were insanely winning!
Real Madrid's squad depth in 2016-2017 was insanely good.
They were better than Pep's Barcelona at adapting to different circumstances and tactical approaches from opponents and finding a way to win a tough CL match; in-particular winning 5 away knockout matches out of 6 in 2017 and 2018 (2 vs. Bayern, 1 vs. Juve, 1 vs. PSG and 1 vs. Napoli) was incredibly impressive. In a big CL match, you could be pretty confident that the Ronaldo-Marcelo link on the left, or Kroos and Modric in midfield etc, would deliver. Plus they did win La Liga matches away to Barcelona, Atletico Madrid and Valencia during that Zidane's 2.5 year first spell.
Pep won 2 CLs and 3 Ligas in 4 years.
Zizou won 3 CLs and 1 Liga in 2.5 seasons (yep, 2 and a half, since the first Liga was basically unwinnable, he even won his only Clasico in that half season, and don't forget that was the MSN Barca side who were quite formidable, having won the treble in the previous season, not some terrible side managed by Schuster or the always average Pellegrini, who make up 2 out of 3 Liga wins of Pep).
And no, Barca under Pep didn't have sheer dominance against continental rivals, I hope that's a joke. They struggled massively in so many away CL KOs. That's far from dominance, meanwhile Zizou has the best CL KO record of all time, meaning results against some of the best of the best, in the most prestigious competition.
Answering you both: Barcelona's "bad" away record is not as simple as you say, as if Barcelona was bad playing away. All needs context. Zidane's Real won plenty of away games playing really badly. They were so inferior to Bayern in both legs in 2018. Pep's Barcelona poor record away was weird sometimes. For example, in the away games against Lyon in 2009 and Stuttgart in 2010, Barcelona played badly and also were going through many players, such as Xavi, having brief slumps. Barcelona always had slumps in February. Still, Barcelona's performances at home against Lyon and Stuttgart were so fantastic that the poor performances away did not matter: 5-2 and 4-0 respectively. In the case of Barcelona's 1-1 draw against Bayern in 2009, Barcelona had won the first leg at home 4-0 in a fantastic performance! They played the second leg against Bayern at a very slow pace. Also, there were some cases, though, in which Barcelona was truly great playing away at the UCL and were actually just really unlucky to draw or lose. Watch the full matches of Barcelona against Arsenal at the Emirates in 2010 and 2011. Barcelona was truly brilliant, but they got complacent towards the end of the matches and allowed Arsenal's comebacks when they should have sealed both ties already! And I would like also to highlight Barcelona's great 3-2 victory over Milan at San Siro in 2011 in a technically fantastic match!
6 players started both the 2014 and 2018 CL finals for them (Ronaldo, Ramos, Benzema, Modric, Varane and Carvajal), while Bale, Marcelo and Isco started one of the finals and came on as a substitute to make a significant impact in the other, so despite the managerial change from Ancelotti to Zidane, that bulk of that team really won the tournament 4 times in 5 years.
By your logic, why not put Barcelona 2015 together with Pep's Barcelona? After all, Barcelona had 6 starters from the 2011 UCL final in the 2015 UCL final too.