I switched from Dropbox to Syncthing after Dropbox changed how their public folders work.
Syncthing is great, open source, secure etc.

Now, of course it lacks the 'cloud storage' aspect of Dropbox... but this can be remedied by installing it on a server. And then you can have as much cloud storage as you like, and you have full control over it. That's the beauty of Syncthing.

And it'll probably be still cheaper than paid subscriptions with Dropbox or other commercial cloud storage solutions.
- Tennouseijin