It may not have stopped entirely, but there are much better safeguards in place, and it's pretty obvious based on power hitting statistics (home runs mainly) that it's not even close to as bad as it was in the 90's and early 2000's. The penalties for getting caught doping are quite high.

Most recently, superstar San Diego Padres player Fernando Tatis Jr. was suspended for 80 games after testing positive for steroid use. [1]

[1] https://www.baseball-almanac.com/legendary/steroids_baseball...

True, but IMO doping is much less of an existential threat to the game than computer-assisted cheating is for chess.