As a front end dev I am all-for vanilla JS. I hate maintaining a webpack, postcss, dependency hell. I still long for the simpler days of plugging javascript into a static page for some helpful dynamic utility.

Where I find vanilla JS struggles is (for example) rendering a big tree of data, and then needing to update some data dynamically within the tree without re-rendering the whole thing. You end up with some horrible queryselector hell, or keeping some immense table of pointers to the elements. Fortunately for us, we have some tiny libraries like lit-html that can help accomplish this. In the theme of grug I think the ideal solution is somewhere in between.

IE users are now complaining that your site doesn't work.

Like I said, stability.

“Can do” doesn’t always (or even often) mean “can do well” or “can do well according to our needs” or “works for all our use cases” or “works for all our users” or…

If vanilla JS checks off all those boxes for you, that’s genuinely fantastic and I’m happy for you. And a lil envious tbh. But there are a myriad reasons I/we currently can’t justify ditching the build toolchain, and most of them relate to scaling in a way that fulfills our requirements. I can’t imagine I’m alone in that.