I personally don't get what they are serving with a home NAS? Movies/Music/Family Photos is all I can think of, personally...and those don't seem that compelling to me compared to cloud.
I've been running a server with multiple TB of storage for many years and have been using an old PC in a full tower case for the purpose. I keep thinking about replacing the hardware, but it just never seems worth the money spent although it'd reduce the power usage.
I have it sharing data mainly via SSHFS and NFS (a bit of SMB for the wife's windows laptop and phone). I run NextCloud and a few *arr services (for downloading Linux ISOs) in docker.
(Currently 45TB in use on my system)
Edit: as no-one is asking, I base my system on mergerfs which was inspired by this excellent site: https://perfectmediaserver.com/02-tech-stack/mergerfs/
I tend to be cloud-antagonistic bc I value control more than ease.
Some of that is practical due to living on the Gulf coast where local infra can disappear for a week+ at a time.
Past that, I find that cloud environments have earned some mistrust because internal integrity is at risk from external pressures (shareholders, governments, other bad actors). Safeguarding from that means local storage.
To be fair to my perspective, much of my day job is restoring functionality, lost due to the endless stream of anti-user decisions by corps (and sometimes govs).
Cloud costs would be... exorbitant. 19 TB and I'm nowhere near done ripping my movies. Dropbox would be $96/month, Backblaze $114/month, and OneDrive won't let me buy that much capacity.