This is probably a small factor -- a much larger factor is just that gamers get bored easily and want to play newer games, even the skilled ones.

Most games will put players of similar skill level against each other, so the fact that there's a cohort of players who are much stronger than you can be totally invisible to your experience of the game as a weaker player, even when that delta is getting larger over time. Whatever skill level you happen to be at, there's probably someone else there too.