It all comes down to which substance folks decide to take for their particular sport. In cycling EPO is popular since it increases aerobic performance and can be difficult to test for at times. Watch the documentary named Icarus to learn more about how not good this all is.
Also no one likes a cheater in any sport. In combat sports PED use can make the difference in brain damage. In cycling EPO can (and has) caused early deaths and heart problems. But in other sports it may not be the worst thing ever. Bodybuilding (is that a “sport”?) comes to mind.
Theres also contrasting ideas regarding steroid use outside of sport. There are benefits to small doses of TRT etc. Watch Bigger, Stronger, Faster on one of the streaming services for their take on it.
I know this a controversial topic but it’s one that creeps in to almost every sport out there. I’m also an MMA fan and of course it’s a huge part of that culture as well.