You obviously weren't an athlete because the mindert of high level amateurs and professional athletes aren't very dissimilar.
I can think of 200,000 differences, right off the bat.
Leaving the financial side of it, I don't necessarily disagree with your premise that athletes can't be happy unless they are constantly competing and, thusly, involved in the sport. The point I was trying to make was that there is a difference between, say, Michy Batshuayi who barely got a game for Chelsea because he's positionally locked out by Costa, and say, Leroy Sane or Alexis Sanchez who can play in multiple positions on the park.
Pep favors players who are versatile enough to switch and swap around, from game to game and even in-between. You get a player who can only play in one position, like Sergio Aguero for example, and it's a problem. Two games on the bench and he's off floating the idea to the media he might move on in the summer. That situation, I suspect, is likely what you're talking about and I mostly agree. Players like Sterling, Sane, Sanchez, B Silva and Jesus have a realistic shot of starting and/or appearing in at least one fixture per week, if not almost all of them, because Pep's hands are less tied with the lineup and formation.
The difference being talent. If you think the players on our squad don't know who's second choice and that the rotation theory will appease everyone ... well then I don't know what to tell you. Just look at kelechi.
I mean, I haven't really expressed this view so publicly, but it seems Kelechi just wasn't good enough. The manager certainly didn't trust him and many on here lost confidence in the lad to make a difference/impact on the game.
I'm not sure the same can be said of the rest of our attacking lineup, which is why they featured more.
TL;DR - I think we have enough games to keep people happy and I'm fairly sure there are some, like say Sanchez, who would be willing to make sacrifices in order for a chance at a Champions League medal.