To be honnest, Nextcloud is kinda a piece of shit software. Every major version break something, an error in an extension can make it crash entirely without any failsafe preventing it. I already lost the database twice (in what... 5 major versions), and the only reason I still use it is because I'm too lazy to use anything not in the TrueNAS apps repository.

It's not bitching if it's true. Nextcloud has really poor performance alone, it tries to do to many things at once and none of it ends up being good. It was amazing for it's time and it's idea but it simply doesn't scale, not technically, not with time. They need to redo the architecture and probably move to something better performing than PHP. I never heard anyone in any environment even considering PHP as an option in 2025.