I have the exact opposite experience but I use their snap which has been updating itself without a single problems or me needing to change any config file for the last 4 years or something. I never need to do anything, so for me the maintenance is the best part of Nextcloud.
I hate that its web frontend is so mega slow that it takes 8 seconds just to log in.
I still use it for calendar, documents, address book and specifically notes too, but I only use external apps for that not the web frontend and the apps on the PC and mobile phone are nice and fast.
I use Syncthing for synchronizing my password manager database. And there the maintainance is also very easy, it updates itself with the system and runs in the background without me ever needing to go to the webfrontend.
I'd say if it's only for one thing, then I'd go with Synthing, because it does not need a server. If I'd use more features especially calendar and address book and perhaps even to share documents with other people then I'd go with Nextcloud.
I personally think a NAS would probably be the easiest option and on top of that they are optimized for low electricity consumption, which a PC, especially when it's older is not. It makes a huge difference because it's running 24/7 for 356 days a year.
I used a PC once and didn't realize that it took always about 300 W so at the end of the year surprisingly the electricity bill was much higher than normally.