Prosemirror seems to be one of the most pluggable block editors out there. For the vue.js community, tiptap is built on prosemirror. Slate (which this is built on) is good too.
Also to add, we are the only self hosted serverless on the market. So if you want to benefit from the scalability and lower price that aws lambda provides, compared to a traditional VMs, Webiny is the way to go.
Here is a partial list of some of the more active wysiwyg editors:
I have personally been happy with Quill (the have their own system for storing text which is interesting.Many of these have active branches, especially in Vue or React etc.