Comments here seem to suggest that Nextcloud isn't worth it. Later today I'm supposed to talk with some folks at IT looking for an in-house file-sharing/collaboration tool that Dropbox/GoogleDrive is (or was, because after GoogleDrive price hikes our institution ditched them). I was going to suggest Nextcloud as a possible option to investigate...
It'll depend on your requirements. Keep in mind that Nextcloud is the largest on-prem collab platform out there, so more users means more complaints... It is used in huge enterprise and government installations so it can definitely work, but it needs a decent setup. For a small company, use the Nextcloud AIO container I would say. For a big one, get Nextcloud Enterprise (starts at 100 seats) to make sure you get any…
Seafile is a close call if it gets more attention to remove rough edges and a bit more feature but interface looks more polished.