I think people just do what they know. Most laypeople that choose Wordpress do so because they want some editing interface. The bloated Wordpress templates are

I think people just do what they know. Most laypeople that choose Wordpress do so because they want some editing interface. The bloated Wordpress templates are a consequence of them looking good in ThemeForest. There's no incentive for template makers to make super fast 100%-static templates, as those don't attract attention. But given the chance, site owners would replace their sites with whatever works. For instance, and a lot of local businesses where I don't have webpages anymore, but only Facebook profiles with a bunch of photos and text. Some of them even have custom domains that redirect to Facebook! Apple App Clips in iOS 14 is something similar: you don't need an App for scooters or for buying Ice Cream, so I foresee some people moving to those just because it's cheaper to make... and because customers will probably be familiar with them.