NAS is defiently a 'what do I want to use it for' question before you dive in. Serving files to multiple devices is the obvious starter for ten, if you have no reason for that, then yes, it's probably overkill.
Most will support Time Machine out the box, and you just set it up, and forget about it. It just does the backups for you, to the schedule you tell it to.
My project initally was File Storage to play movies on Kodi on my big screen TV with an always on torrent client, that wasn't as power hungry as a desktop PC.
Over time (and an upgrade from the initial one) it's turned into my hub for data and entertainment and as much as possible is automated.
It's a web server for testing web dev stuff, it automatically backs up my personal data to the cloud, runs docker with a ton of containers (plex, jackett, Transmission, radarr, lidarr, sonarr, soulseek and a Firefox browser that all run though VPN) provides easy access to my files from any device from anywhere, is just one device to back up, so saves me effort and time, has been connected to VPNs, has been a VPN Server for access to my Local LAN (no longer does that as my ASUS router now does that bit) a wake on lan portal for my jump box when I needed to use a full phat Windows client based on my local LAN from remote.
I've had 2 over the past 10 years, the first one ended up being underpowered as I realised I could do more and more with it, so upgraded to a 2 bay small business class one, and has two mirrored 5TB drives. One of the best gadgets I've ever bought and couldn't live without one now. It's essentially the central hub for all my data and entertainment. And once you have things like Plex/Sonarr/Radarr etc all set up perfectly and working nice you just forget about it and let it go about it's business.
Don't get me wrong the initial outlay is expensive, the setup can be complicated and probably shouldn't be attempted by anyone without a little bit of IT knowleedge, you need to security patch especially if you have open ports through your firewall to it, and well yeah, it takes a long time to setup perfectly with lots of trial and error, especially if not using the out the box solutions provided by the vendor, which tend to be a bit limited. Although the out the box backup tools are very good.
Like the majority of hardcore downloaders, when I could go to the cinema, I go loads, my DVD/Blu-Ray/4K disc collection is large, and I sub to Amazon Prime/Netflix/Apple TV+/Apple Music, so while stuff is still obtained perhaps not so legally, the stuff i enjoy either gets watched on its correct platform if it's available (Unless it's on Sky basically, fuck you Murdoch) As I can just tell Sonarr, oh that film looks good, grab it when it's available..... I'll forget about it, until it automatically grabs it, and then I go 'oh yeah, i wanted to watch that, music gets streamed legally unless I want to specially shuffle certain types of music which the online services seem to be shit at, so I then do it via plex as I know it's only going to play music I love then!
