Been looking for something like this but minus React for _ages_. I'd like our users to build their own RTE according to their needs, having a common data model on every one of them.
Would second ProseMirror. It was powerful enough for me to build essentially a code editor: https://qworp.com/
Would third prosemirror. Used it extensively for years
Based on ProseMirror, more popular than raw ProseMirror, inspired by Slate (years ago), but framework-agnostic and more advanced in some areas (like collaborative editing):
Slate is architected so everything that actually involves React is in a separate plugin called "slate-react". As explained here https://github.com/ianstormtaylor/slate#packages there's a package called "slate" that's "Slate's core data model logic.", and there's another package called slate-react that is "React components for rendering Slate editors.". For example, I just searched npm and quicly found "slate-vue" (https://www.npmjs.com/package/slate-vue) which is Slate, but with a Vue plugin instead of React.
Quill is ok
My quibble with Quill is its long-standing and may not ever be fixed lack of support for tables.