How would Babe Ruth do in modern major league baseball? Would he still hit 60 home runs one season? Could he win 20+ games, several years in a row, as a pitcher?
Without a time machine, it's impossible to know. Yet in every sport I know of where you can objectively measure results, performances have gotten much, much better since the 1920's. I think it's often or always true in sports where performance is harder to measure. Tennis, gymnastics, figure skating, etc. If you think Bobby is the exception to this, I think you need to explain why.
Also, there are something like 25 or 30 times more golfers than in Bobby's day. The game, both pro and amateur, has exploded in popularity. That works against Bobby, too, IMO. He was a huge fish in a small pool. Could he still be a huge fish in an ocean?