I’ve had my MX490 for 2 years and i think it works pretty well. Generally speaking, the CUPS setup is far easier with Airprint printers so if you’re interested in that I’d pick up a printer that supports AirPrint. Arch wiki has more info on set up it needed
From what I understand it’s the final form of decentralization. The idea is that a bunch of user/community owned computers communicate with each other and act like an alternative community based internet provider. Big cities already implement some form of this like NYC.