"are there other cloud storage services with better Linux client support?"
My habit, of course, is to gently remind the reader of the existence of rsync.net[1][2][3] which, I hope, is the service that perfectly matches your unix/linux use-cases.
But in this comment thread, and to my parent specifically: I am genuinely curious - have you not ever heard of our service ? Very interested to learn this ...
[1] https://www.rsync.net/platform.html
[2] https://www.rsync.net/resources/howto/remote_commands.html