And that would be what? Exactly?
I did a personal project last year that was vanilla HTML/CSS/Js, with some templating in Go (I know it's templating isn't the best, comparatively). By the end, I wish I would have done it in React. I ended up re-inventing the wheel for a lot of things, and ended up with something that was decidedly messier. All while attempting to be more simplistic.
I wish Web Components would have taken off. When Polymer first launched, I was totally on board. I loved the idea of writing vanilla frontends, and using Web Components where I needed extended functionality (vs a full framework). But, it didn't, and unless your site is super simple, and mostly static, React et al. are the best ways to create frontends.