Thanks for reminding me that I still need to try out NextCloud. I never did much with the free provider I signed up for because I didn't trust them with my data.
What are your syncing/sharing needs? Mine are fairly simple, and I don't need a lot of storage space. And I don't really sync data between many devices very often these days. It's mostly either cloud backup or sharing files.
I've been happy for years using BitTorrent Sync (
v1.x) for sharing/syncing large files as needed. (I have backups of the v1.x installer files if you need them.)
I use
Keybase for a few public files, but mostly for some private backups of important, but not huge, files.
For one-off sharing I've recently discovered and started using
Firefox Send.
And of course, I do still have and use Dropbox, but that's mostly out of momentum (i.e., laziness).