Seafile is great…with caveats that seem to bother people away from it:

1. Files are stored as git-like chunks on the server

2. Features behind a paywall for more than 3 users (Pro vs Comminity versions)

3. Documentation can be very confusing at times

Item 1 can be mitigated by utilizing tools like Rclone to mount the files on the server, reassembling the chunks, then back up and unmount when done. Item 2 isn’t a deal breaker for me.

It is super fast and reliable in my experience. I specify wanted the selective sync because my stupid MacBook has a tiny SSD, but I still wanted access to files from other device libraries.