Steroid use is illegal first of all (unless prescribed for specific injury).
In the game,as well as in society.
Second, if Tiger's using modern equipment, he's competing against other players that are as well.
If a player in baseball is doping, he's doing something other players aren't.
thirdly, the courses are expanded (not quite to the degree that equipment is aiding distance).
That said, I'd love to see a rollback in shaft material(weight) and balls.
Tiger's gap would grow, not shrink.