I really don’t blame them, security and privacy minded folk are more likely to use niche configs. Feels like for Linux stuff companies may be better served making APIs and letting the community handle it. Rclone for example implements a bunch, and last I knew had an unstable Proton plugin.

I was in a similar position and moved to Proton. Their native Linux support is rudimentary, but nobody else provides a better, privacy respecting option. Their web apps work well though, and the email client uses local storage APIs for offline use and search.

I do use Mega for cloud storage though, they’re e2ee and have solid Linux (both GUI and really nice CLI) and mobile support.