These also have the advantage of being nice and quiet, which if you are going to have it in your house rather than a hot garage or whatever can be nice.
I bought a NAS, later realised that it supported Plex and Jellyfin but it was often too slow to do the transcoding. I still use it for storage but there were no real upgrade options. It was cheaper to get an old NUC, rather than replace the NAS with a high spec one to be able to run Jellyfin properly.