> So I get it that if really want to go snorkeling or mountain biking with a camera, this might be a good choice, but that's a tiny market, and for everything else, why would you buy it?

I don't think people are cross-shopping action cameras and mirrorless cameras. Either you want a wearable light-weight shockproof, waterproof camera or not.

Worth pointing out that your experience is with a model from a decade ago. The current Hero model is the 13.