The main cloud services don't even work natively (GoogleDrive, OneDrive, iCloud) basically the only mainstream choice is Dropbox. I tried to use Google Drive in Mint, and it's a pain to get it to work, and usually it stops working after computer restarts.
Someone has a recommendation about how to handle these services?
Just to be clear, Syncthing is not cloud storage but file syncing. It can be used in a similar way but it does have different strengths and weaknesses.