Another vote for Lit here.

JS frameworks were invented to deal with clunkiness of Vanilla Javascript and got bloated to include everything and the kitchen sink. All of a sudden they're 'ecosystems'.

Modern JS + Web components with the light layer of Lit on top solve at least 80% of the issues there were and are with just plain JS. Close to actual web standards and thus play nice with almost everything. By design they fit into a far more modular approach than React or Vue or Svelte.