Given the ease of implantation of end to end encryption now, it’s a reasonable assumption that anything not e2ee is being data mined. E2ee has extensive security benefits, for example even if your data is dumped the info is still useless. So, there has to be a compelling reason to not use it.
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.