"Other services like Dropbox are also fine if you have a sufficiently high entropy password" That's why you add that binary key file to the mix that you libera

"Other services like Dropbox are also fine if you have a sufficiently high entropy password" That's why you add that binary key file to the mix that you liberally distribute to all your devices. But that you carefully keep far off your sync platform. The danger of a weak password is when a device falls into the wrong hands, a compromised sync platform is much less of a concern (if the file is in the mix).