The last three WC winners exited the group stages at the next tournament, the current EC winners failed to qualify for the WC not 12 months after their triumph. France had a rather disappointing EC after winning the WC. So yes, I think most tournament winning teams don't play highly functioning top tier football. And aside from the English few nations go into a tournament feeling certain that they are going to win it. It's just something that happens.
Regarding 2014 things didn't get a lot better once the tournament started either: the games against Ghana and Algeria were just bad for a title aspirant. But in the end they won the cup, so every game was great after all, Höwedes became a top LB, Mustafi a top RB. The defense that made their GK the MVP was infallible, the attack that only produced in one knockout game and had to rely on a defender's goal and extra time in the other three games was elite too.
Which makes what Germany did over those 8-6 years even more impressive by reaching the semi-final in every tournament, something no team had done during that era and few have done previously.
We began the the 2014 World Cup with a host of injuries. Leaving out the fact that Gundogan and both Lars and Sven Bender were injured for the tournament, Schweinsteiger and Khedira entered unfit, which was why Low had to go with Lahm in central midfield for the first few matches. Hummels was also unfit throughtout the tournament and was replaced with Mustafi against Ghana and Algeria at RB. Mustafi didn't play at all after that so I don't know why you're judging a team based on someone who played only twice.
Our attack wasn't awe inspiringly amazing, granted, though Spain again were winning most of their matches 1-0 in 2010 as well but no one will say they were crap, but again we were hamstrung with injuries in that area since Gomez wasn't available as a backup to Klose and Reus, the best German player at that time, was also injured. Despite this we still scored a decent amount of goals against good teams.
I honestly don't know why you're so depressed over the 2014 win and make it out as if we were lucky to win or weren't that good a team. We had one sloppy game granted against Algeria but that was down to the extreme tactics Low imployed, and also not having Khedira/Hummels available so Mertesacker/Mustafi played. Also, you can say we were lucky but the reason why we played with such adventurous tactics was because of Low's faith in Neuer's sweeping ability, so he would say he was vindicated in that decision.
It's ridiculous to take down that team we had just to make a point that our current team is good. Tell me, who from the current team would you have over the squad we had from 2010-2016? Kimmich would be it I would presume, over Khedira? Khedira was an amazing player himself who fit into that team perfectly as a foil to Schweinsteiger and Kroos/Ozil so that is debatable.