It is, but up to a point.
The competition aspect is vital, as it's what draws the best players to the field. Trotting out a fat 50 year old would be entertaining, in a #failarmy kind of way, but he'd suck and not help his team win.
Sports viewing is generally correlated with mastery and skill of the athletes. pro attendance > college attendance > women's sports, etc.
Athletes are drawn to sports to show how good they are, win games, and find out who is best.
The more we screw around with that, the riskier it gets.
I could see professional sports as we know it falling off a cliff 20 years from now, having sold out on entertainment and eschewing actual competition.
I don't think it's LIKELY, but the intro in the movie BASEketball could easily happen. We're in a post-truth, 9-second attention span world and baseball with football safeties taking people out or basketball requiring 1 woman on the court at all times is possible. Anything that gets 1 more click or like is a possibility.
While it's far-fetched and unlikely and perhaps silly to talk about, how would it start?
Players making more money pitching products than pitching baseballs.
Kids getting paid millions before taking a snap.
Teams finishing a distant 2nd (or 3rd) place, but being crowned champions.
A season-ending conference championship outcome being irrelevant.
Losses in a short regular season lacking any consequence in the polls.
And so on and so on.