Stopped reading there, basically. You make a good point in general (and the other players named above are indeed pretty decent), but Milner? 'Pretty much ever team in the world'? You think Milner would be getting on the bench for any of Bayern, Barca, Madrid, Juve, Dortmund, PSG, us? He's one of those 'solid, does the basics well' sorts who ought to be a mainstay for Everton or Sunderland. If Mancini had bought some decent wingers, with the intention of actually playing them, instead of blowing £50mil on crap this summer, then Milner wouldn't be getting a look in.
I know someone would quote me just because I included Milner there. I know he is decent player, and that's about it, but people here are talking about him like he is championship level player. It's not like he is their worst player, I have seen him having good game when the likes of Silva, Tevez, Aguero and Toure all had poor games, and that happened a lot of times. But, let's compare him to some other squad players in those teams you mentioned(not necessarily his position):
Bayern: van Buyten, Rafinha, Pizzaro, Contente, Tymoschuk are all squad players and at least two or three are included in their team every week, and I would have Milner in my team over any of those.
Barca: they have a lot of exciting and talented players even in their B team so I won't argue too much about them, but surely he is better player than the likes of Tello and Cuence were last year, and they got a lot of playing time last year.
Madrid: Granero played lot of games for them last season, Callejon also, and they aren't better players than Milner. Then you have Essien who isn't half of player he used to be, and couldn't get game in Chelsea last season, but still played a lot of games for Real Madrid this season, same goes for Albiol who is far from Real Madrid quality and he plays some games from time to time.
Juve: they have lot of mediocre players who are starters every week for them, let alone on the bench.
PSG: You think Beckham would get any game time at City, Real, Barca, us, etc?
Dortmund: Santana, Leitner, Scheiber?
Every team has decent players like Milner, or worse who get a lot of games during the season, that's why they are called squad players after all, and Milner is squad player, nothing more, nothing less.