Am I the only one here that got really bad experience with nextcloud and didn't figured how to make it work correctly?

I'm talking about painfully slow login pages, ages to show files, even upgraded hardware with disk entirely capable of saturing full gig network connection and still...
Getting only about ~30ish MB/s when downloading from nextcloud.
Incredly slow document loading with collabora..

Even if my hardware is not new-gen, a app like immich works flawlessly and loads everything instantly.
Is it the fault of next cloud or am I doing something wrong?
Are alternatives like seafile or openCloud better?

Willing your help fellow selfhosters