Do you need it though? i feel like the linux userbase is already fairly low, and the intersection of people who cant do a RW mount with rclone ans uses linux is even lower.
You would be pouring a bunch of money into a development for the 0.001% Userbase
You can tell how passionate a company is with their products by their Linux support. That means no one there cares enough to push hard for Linux support. Even Dropbox has a Linux client.
You're absolutely right, official version doesn't exist. The closest thing would be this: https://github.com/abraunegg/onedrive/
My brain was confused with Mega's excellent client.
SORRY
I recently did this, and it was fucking annoying to create the app in Google's Cloud. Incredibly laggy (5-10 seconds until clicks register), loading times of up to a minute between navigations.
This was on a very beefy PC, I suspect the issue is that I used Firefox.
Just use rclone. Its bidirectional sync is kinda meh last I tested it, so I do manual syncs in each direction. Otherwise its awesome. Can even encrypt your stuff with your own key.
Supports a bunch of backends. There is an androind client called Round Sync with cron-like scheduling to keep my phone backed up.