Sure, for devices that already are logged in then yes. But to log into my Proton Drive I have to enter my password and authenticate with my Yubikey and it might not be a trusted computer, or the internet connection might be slow. And my self hosted services including my Seafile are behind a VPN so I’d have to log into my VPN on that PC to access them. I definitely transfer files by USB on occasion.
I guess I can put a VPN config file on my USB in the encrypted folder so I can connect to it from any trusted PC