Depends on the Pi in terms of how much you can do, but yes.

I have a Pi 5, and I’m running Pi Hole, Nginx porxy manager, Jellyfin, Syncthing, Paperless NGX, and a full servarr stack (including Qbittorrent and a VPN). No issues; 4.6 gb out of 7.9gb ram in use, and no appreciable bottlenecks.

I would just caution that things like Jellyfin are a moveable feast - I am 1 user streaming content on my own to 1 device without issues at 4k. But more simultaneous users and if you start depending on transcoding your mileage may vary. So yes Jellyfin and other services will run fine, but any server can be put under pressure if it’s not adequate for the actual usage.