> Why did we let mobile go down the one-app-per-website path?

Because the web is still barely usable for anything more complex than showing a few lines of static text and an image?

Because for almost as long as (modern) mobile apps exist the web was even less usable?

Because even now you can whip up a fast complex mobile app with 60fps animations and native behaviours probably in minutes? While on the web you're lucky if you can figure out which state/animation/routing library du jour isn't broken beyond all hope?