I wish Office 365 would hire someone like the author. Online Word never renders the same as it would in the Desktop software...and this matters. I deal with only modestly complex documents when I write grants but I do need to stay within page length limits for sections, I need some layout stability...so I inevitably fire up my Windows VM to run the application.
Before anyone suggests LateX, I know, I know, but when you write collaboratively, you don't always get to choose the platform.
Microsoft had a blog post somewhere talking about how they're using desktop rendering code via wasm and canvas to get to parity.
Don't know how complete that effort is though. Haven't checked myself.
Google has switched in 2020 (if i am not mistaken to canvas), but I am not saying this would be the solution to everything, It is just another option one could do. I do not know if someone noticed this, but that is part of the reason you could not just open google docs on mobile. Because I would suspected that it would been too much effort for them back than. In anyway Tasfer tried as best as possible to do that on mobile too.
Was actually going to suggest Typst.