I work with a technical writer(who also writes novels) who has these very same pain points listed:

Gutenberg not ideal for tech writers, feels more like a designer tool
Missing writing formats i.e., paragraph indent, toggles, notes, tips, etc.

Mainly we use WordPress to publish help sites for our applications and her preferred authoring tool is actually Madcap Flare, not sure what she uses for drafts. Flare is more of a component content management system (CCMS) - https://en.wikipedia.org/wiki/Component_content_management_system

Many of the writing strategies here seem to paste their copyright into WP
and then touch up with layout/design. Reassuring to hear that.