Simple to use NAS software. Has a unique raid model that allows adding as few or as many discs as you like of whatever size. You can start with 3 and add 1, 2 or more to the array, no issues. The parity model also lets you add as many parity discs as you like, as long as they are the same size as the largest disk.
Had early docker support as well, so it’s easy to spin up and integrate docker apps on the same server.
Lastly, they used to sell an excellent 8 bay standalone case. Think its been some years since they did.
Self hosting and syncing data to a 3rd party would give you total control of your data and data resiliency.
Sounds like a good combo that’s lacking now.