Earlier quoted context omitted.
Home directory encryption via ecryptfs is now the default in most Ubuntu variants, and it would be insane not to attempt to support it. That said, given that my Dropbox subscription just renewed (and that Linux is pretty much the only reason I'm still using it, since there is no OneDrive client I can rely on), I am really sad this seems to be a future direction for Dropbox.
I use Google drive, but the Linux support was awful and I started using insync. It's about $25 for a lifetime license and I love it. I run Ubuntu with encrypted home and have for years. It works great and I highly recommend it, and I don't work there, just a happy user. The Nautilus integration is decent too.
However, my IT company onboarded a media-intense client with insync and it has been nothing but a nightmare. There are hardcoded limits (like only syncing two files at a time, IIRC) that make it effectively useless for anything beyond small, personal use. It's cheap and you get what you pay for.