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.