That's not the reason.
Athletes do unsafe things all the time, with the blessing of their sport. Boxing is unsafe, American football is unsafe, skateboarding is unsafe, skiing is unsafe, extreme sports are unsafe, etc...
The prohibition on steroid use has more to do with fairness and ensuring a level playing field, so no athlete has an unfair advantage over another.
Such considerations are irrelevant when one's goal is not fair competition but advancement of science.
This is somewhat circular logic - it's only 'unfair' because you've defined it that way. IMO the idea that there is a level playing field is somewhat of a myth to begin with, there are plenty of other ways to gain "fair" advantage like better training and nutrition, and access to those things is clearly not equal across all competitors. I think you could probably argue the current situation is less fair than just allowing them considering how many top athletes likely use steroids anyway and just haven't been caught.
That's not to say that I think we should allow steroids in sports, just that "a level playing field" doesn't seem like much of a justification to me. I think the simpler reason is that lots of sports already have rules to make the sport safer for their athletes, and banning steroids/drugs simply falls into that same category because it has a clear risk of spiraling out of control. Yes, sports are unsafe, but they're also generally designed to not be so unsafe that competitors are dying all the time due to going to extreme lengths to try and win.
I think your take is overly zealous, if you are really worried you could make it a requirement for grants. Which it already is.
edit: Maybe for a different framing, picture it more like climbing a mountain. You do it because its there, it is that simple. All the rest (sponsorships and the like) is just ways to get funding to get you up there. You were already going to go, more funding just makes it saver. And as unhealthy as it is, i think society should not get involved further as me not dragging anyone else in with me. After all, how is this any worse then eating or drinking myself to death. Or giving myself a heart attack (to come back to professional athletes)
