For many years I used Dropbox to keep an on line copy of my files, mostly to share them between different computers. Eventually I reached the limits for the free subscription, then I tried different hacks to solve the problem.
At some point I decided to buy a NAS, and that sorted many of the issues (in particular with full backups, which were all the time a concern with all the computers running around the house).
On the last few years I moved everything to the Synology Drive Client application, which works very well. There are clients for Windows, Mac, Ubuntu and Android, which covers most of my platforms.