Connecting to the network does not have to mean connecting to the internet. Basically every consumer grade router out there is capable of restricting a device to the local network only. It could reach other devices on the network and the other devices would be able to reach it, but it would still be cut off from the internet.
I totally get it and agree, but does this mean you use an USB cable at all times to print things ?
Either USB connected to one PC which shares it, or just block it’s Internet access in the router firewall
Connecting to the network does not have to mean connecting to the internet. Basically every consumer grade router out there is capable of restricting a device to the local network only. It could reach other devices on the network and the other devices would be able to reach it, but it would still be cut off from the internet.