Did you switch Nextcloud from SQLite to another database?

Other than that, chances are, whatever makes your Nextcloud install slow will also affect Seafile or whatever else you replace it with.

I spent some time with top and iotop debugging my server performance problems. I found an issue that was completely unrelated to Nextcloud. Since I fixed it my Nextcloud instance has been completely reliable.

I looked into Seafile as well but disliked that it stores my files in some weird block format.