Personally, I’m almost convinced I could live with something cloud-collaborative like an Etherpad - for example https://pad.disroot.org/. What is it about wysiwyg that makes folks want an ‘office’ style writing tool, with all its clutter?
Is it tables?
For a couple of years I’ve worked routinely in Markdown and am happy now just to drop into a word processor for formatting and page layout of final pdf versions. I’m fussy about design, but I find Markdown is good for everyday processes of writing and collaboration.