You are comparing apples to bean and cheese burritos here.

FTP/FTPS/SFTP aren't even close to the same thing as a fully integrated cloud solution. Sure you can use both things to simply transfer files between several devices, but that's not why the only reason most people use a cloud solution.

It is conceivable that there could be a cloud solution which might incorporate the use of SFTP/FTPS as an underlying protocol, but I think the go to is HTTPS for myriad reasons.

NOTE: if you are regularly using one of the FTP-like tools to sync files as part of your regular workflow, you should look into rsync