> The body doesn't care if you took steroids with a prescription or without one.
The body doesn't, but the person who prescribes the medication does. With any medication there are tradeoffs to be made. A doctor is usually able to make a more qualified assessment of said tradeoffs than the average patient.
After all, the tradeoffs of taking anabolic steroids are plenty, especially when taken over longer periods of time.
And not to mention the fact that the stuff people source illegaly is rarely chemically as safe as the stuff used as medication.
> He's still alive.
He is, many other high profile bodybuilders aren't. While that's not a medically meaningful statistic, these are the people whose aesthetics young men strive for.