I bought a generic N150 based minipc for a firewall & router (running OPNsense), and repurposed an old desktop PC as a server to host immich, paperless, nextcloud, etc… I considered both RPi and mini pc for the server, but I needed a few TB of storage and wanted redundancy. Spinny disks were a much more affordable option than SSDs, and minipcs and Rpis tend to not have much space for those drives. You can add on storage to them, but then they just become clunkier and more expensive than the old PC I already had laying around. Power consumption is probably a few watts higher on the PC than a Pi would be, but it’s not terrible.
That’s why I went the direction I did. I’m 3 about or 4 months in, and it’s been solid so far.
I installed AIO on an old machine (retired gaming PC) a few months ago. I use NC notes and file sharing, and have disabled other services I don’t need. It’s running behind a proxy server. It’s worked fine so far. I use Immich for photos though, not Nextcloud. I heard a lot of gripes about Nextcloud for photos.