I think people get into the mindset of needing to go nuts when exercising/health or they need to be at a gym. All they need to do is be active for about 30 minutes each day by going for a walk or biking.

Many cultures and countries ranked as healthy, and I mean overall like children to elderly are places where people walk everywhere. They aren't all power lifting or even going to gyms.

Strength training is good but overall daily activity is best.

True, but statistics has nothing to do with correctness. Something done in excess, in either direction, is done in excess regardless of how many people do it.

The via media comes with difficulty as it requires reason and discernment, whereas extremes are easy and mindless, and people either under-exercise (the more common case) or over-exercise.

But historically, I would argue that we see more extreme "fitness" fads today than we did previously. Really dumb stuff that no longer has anything to do with health or fitness or beauty and more to do with some weird obsession.

We're talking about the set of people that actually weight lifting exercises, though, not the population.

Someone that goes for regular long walks is better off than a powerlifter, I doubt you would consider that a convincing argument against the gym.