A couple thoughts:
There are undoubtedly many, many guys in the NBA who use anabolic steroids or other PEDs. Look at Giannis. The kid is huge now. Given his frame and natural ectomorph metabolism/body type and the extreme caloric toll of an NBA training regimen , I mean, be realistic. But honestly, why should I or anybody care if these guys juice? I don't watch the NBA because I see myself in the athletes. I want to see freaks do freakish things.
Finally, say LeBron takes a pee test and is found to be a massive juicer (not unlikely). Does the NBA go public with the info? Think about it.