The beauty of a NAS on the network is anything and everything can access it, it's self contained, doesn't pull much power and can be put anywhere. The bigger ones of course have more fans and make more noise, but I retired my 5 bay Synology as I simply didn't need all that storage and went to a fanless single bay NAS. I would always maintain my own local network storage.
But like the OP, it is getting old and I recently backed up everything 'just in case' it fails.
It's a catch 22. If you want a full blown extremely powerful PC in your audio/video system, it's going to make noise. If you just want to watch movies, Netflix, blurt on the internet a bit, a silent small form factor PC is fine.
Running long cables from a PC in another room or in a cupboard is not my cup of tea either.