Easily! My Pi runs PiHole and a print server and I’ll could probably run almost my entire stack in it if I wanted. Jellyfin would be the hardest due to transcoding CPU usage, but it’s probably ok for one stream at a time.
The other issue for me would be storage. Since I have a 32TB NAS I run everything that requires large storage on it, but a USB RAID attached to a Pi would probably work just fine.
The other issue is RAM. I rarely hit 8GB, but do use more than 4GB fairly regularly.