In reply to Bastian.

Agreed more examples are needed to help learning by imitating, which I concur is super important. Would expect to find those in the main documentation handbook or elsewhere?

While blocks are one of the most important APIs, there's still a lot of work put into other ways to extend the editor interface. If you haven't, check out the reference guides in this section which cover a lot pluggable areas: https://developer.wordpress.org/block-editor/reference-guides/slotfills/

This is still a beta, but the Block Book is meant to be a good way to inspect different blocks and get a reference for how to style them.