There are lots of guys who aren’t good enough to play basketball at BYU, but could play at a DII, DIII, or NAIA school, that choose to just go to BYU and not play basketball.
You’re assuming that the dudes playing on the flag football team are the best flag football players. They’re the best flag football players who choose to play flag football for a living. Take this Doucette guy, the QB who thinks he’s better than Mahomes. Do you know what his job was before pro flag football?
He was a ramp agent for Delta Airlines. Of course he’d rather play flag football.
Just because someone plays professional flag football doesn’t mean they’re the best at flag football when they don’t make any money. If the money was there, maybe you’d be right.
Putting all that aside, even if these guys were beating out the top college football guys who didn’t play in the NFL, do you know how big the gap is between fringe NFL guys and All Pros? It’s huge.