They haven't been making it super clear, but you can actually create, edit, and share text documents in Proton Drive right now! It's just not a separate thing like with Google.
I would REALLY love a linux desktop application, whether that be rpm, deb, or even flatpak. Give me a desktop drive based program, and a native email client that doesn't require installing their bridge which was clunky at best last time I tried it, and I will be elated!