Ask HN: Keeping javascript simple, what are our options?

Self taught dev here. I have had two experiences working in front end development. The first is basically script tags in HTML. HTML is built by bottlepy template engine. *.js files sat in the /static folder on the server. Javascript makes json calls to server with a database etc. Pull in Bootstrap and projects can be put together super quick works well.

The second is a recent unplanned deep dive in to Angular CLI which to me seems at the opposite end of the spectrum, single page, Typescript, NPM, compiled js etc. Fun, but Full On. But for as much that this brings, a lot of things that just worked before are complicated.

I recently started a new personal project. I have started with my comfortable bottlepy sever with templates. But as the javascript becomes involved, more libraries seem to give examples in the ES6 style (imports etc), I think I need to think this through more.

My question is, in late 2019, if you want to keep your javascript simple, what are your options? There must be something that sits between plain javascript and Angular CLI. No Angular, React, Vue etc. Think more like leaflet.js with a few plugins.