I’m excited to share BlockNote, a block-based editor on top of Prosemirror / Tiptap: GitHub - YousefED/BlockNote: A "Notion-style" block-based extensible text editor built on top of Prosemirror and Tiptap.. Or try the live demo here.
… and plenty more (drag 'n drop, collaboration, placeholders, etc.).
It’s not “feature-complete” yet in terms of blocks, but I think people have been struggling with building a block-based editor on top of Prosemirror (I know I have), and hope this project can be helpful!
Where Prosemirror really offers raw building-blocks, BlockNote is more opinionated and comes with a UI out-of-the-box, so I hope it will be easier to integrate into your project if you don’t have the time / resources to start a PM editor from scratch.