Things to consider…
>>> Which services do you want in addition to Time Machine backups?
Basic file sharing is common to all, but streaming 4K video or hosting Windows virtual machines requires more power.
>>> Can the NAS cope with increasing storage requirements?
These invariably grow with time, so you’re likely to want a system you can upgrade with larger hard disks.
>>> Do you also need backup support?
Families may be happy keeping copies of important documents on iCloud, but businesses need proper protection with remote backups stored in a cloud service.
>>> Do you need to tune the configuration for performance?
Future macOS may require SMB connections, and adjustment to settings for optimum results.