The problem with this line of thinking is that, at a level where everybody on the team can throw/catch (not some 10U rec team), literally every single player out there can receive a throw or catch a pop-up or be a relay person. Those are all basic skills, and that's why the position is less valuable. "Important" is the wrong word because, yes, all those things are important, but they're also fundamental to the game. There's nothing special about them.
Fielding ground balls is important, but 1Bs field fewer of them than the other positions, so it's less important. And run-downs don't happen nearly enough to be a real consideration here. You can put your stud CF at 1B because she's good at run-downs. I'll keep her in CF where she will have more opportunities to help a team win games.
Again, there's a reason why, for the most part, players move down the established defensive spectrum as they get older, suffer injuries that sap their ability, etc., usually ending up at a corner OF spot or 1B (or DH). And you don't see many SS or CF end up at 1B because, generally, the bat doesn't play at 1B when (again) almost the entire population of players can play that position, including all the best hitters.
