Lots are. Lots aren't. There are a variety of leagues and federations that test frequently, both in-competition and out of season.

We know they're almost certainly keeping these clan because many weight classes in Olympic weightlifting have had significant drops since the steroid era, being unable to overcome them even with significantly better training knowledge, processes, etc. - the testing is catching them. Many of those olympic lifters lag only slightly behind the similar tier of powerlifters in the drug tested leagues on squats, with the difference there being largely because for olympic lifters the high bar squat is an accessory exercise and for powerlifters they get the benefit of the low bar squat + it being their primary exercise, and a significant component of strength is part of your nervous system adapting to specific movements. If these powerlifters were all at supraphysiological levels of testosterone through gear, they'd be blasting way past the olympic lifters.

I also still don't totally agree with you on the other aspects, either. We have studies that show weightlifting and cardio are equally important for a very broad variety of risk factors. For example, preventing or managing type 2 diabetes is better done via weight training vs. cardio, way better blood sugar levels, etc., and being diabetic significantly raises your all cause mortality for a huge number of things. Do both. And most of the basic health benefits for lifting are at volumes that are pretty easy to achieve even on limited time, both for strength and hypertrophy based loads. And you'll get plenty of hypertrophy even on a strength-focused plan when you match for volume, you just won't be maximizing it the way bodybuilders are. As for age related decline, you still have to lift either way - it's not like you build up a large enough reserve to lift through your 50s on a super hypertrophy fixated program and then stop and still have muscles through the end of the decade. If you stop training, a bodybuilder isn't going to last much longer than a powerlifter on the having muscles part. If you keep training, both should be able to maintain proper amounts of muscle mass for their age and genetic makeup, and if you have concerns around joints or similar you can always move to a more hypertrophy specific workload when you get to that point. It's not like you've got to learn a whole new skillset.

I don't understand your arguments.