So to prove your point you choose a random footballer from now and compare him to random footballers from the early 90s. I’ll try that, too. Cristiano Ronaldo is fitter than Brolin, Molby, Southall, Ruddock and Bosnich were. Wait, that didn’t prove anything.
What I'm trying to say is guys like Romario, Laudrup were still exceptional football specimens who would be electric in the modern game (that is just a random pair of players).. and someone like Mata heck even Messi, they're not ultra fit modern day footballers. Messi of this year is not the fittest he has ever been, yet he's still comfortably the best footballer on the planet.
That tells me that quality still trumps fitness.. if it was all about fitness, then Ronaldo would be the best player in the world. Quality players who are not super super fit but just normal level of fit for a professional footballer, can still more than hold their own in the modern game if they have the football brain and skills in their locker.
So this concept of a ultrafit modern team completely thrashing a top top team from the late 80's and early 90's seems unrealistic to me because quality wise that Milan team or Barca team from that period had top class footballers who I would still back against teams from this era.
Overall fitness has definitely improved, I never said it hadn't but I think people overstate the condition of todays players to the past when comparing the quality of the elite teams to the elite teams of that era.
Someone said Barca 2016 as fit as Barca 2009? no chance, Messi was much more fitter and faster then.. he was pressing alot more, beating players more, scoring more.. his general output in terms of effort was more. Iniesta was fitter then, the amount Xavi would run in games is alot more than Rakitic, Dani Alves was covering insane amount of ground.. this current side conserves energy more than that team did.
The United team of the 90's ran more than this current United side does.
Football like any sport goes through peaks and troughs.. fitness of players doesn't consistently get better year after year, there are times when it goes backwards before it goes forwards again. Overall I would say football is getting faster paced, players on the whole are definitely getting fitter but that doesn't mean every season this is happening.. last season alot of the elite EPL teams were in decline and covering less ground than they had in yesteryear.