They offer the ease of use of a plug&play piece of hardware with its OS specifically designed to run not just a bitcoin node, but a full cohort of self-hosted apps that you might want to run on top or aside.

For example, you might also want to run lighting core on top of your bitcoin core node for the LN, with Ride the Lightning and BTCPay on top of that and some other apps to help you manage your channels and liquidity. You might also want to run a private relay for nostr, your own cloud storage service and some other self-hosted stuff.

All of that, can be done with your own hardware, either installing an OS like start9, or software like umbrel and others. You can do it on a Raspberry Pi, a spare laptop/desktop.

So the main thing, imho, is whether you have the spare hardware to do it, our the spare cash to buy the plug&play hardware.