I’m a big fan of unraid but I will admit it’s overkill for a simple media server.
A synology NAS should be plenty powerful enough for most streaming needs so long as you’re willing to let your media transcode first and you’re not streaming to too many devices at once.
I use my unraid NAS to run sonar/radarr/readarr/prowlarr, stable diffusion, myjdownloader, a few vms and at one point even my lemmy instance. But honestly aside from stable diffusion and the VMs a synology NAS should have enough power to run a handful of other apps in addition to plex/jellyfin