Airgapped devices are also good if you know what you are doing. You can also use airgapped device for seed generation. As long as you format the device and reinstall its OS with the Bluetooth and WiFi card removed, then you have nothing to be worried about.
I wouldn't trust entirely airgapped devices.
Even airgapped machines might be infected via BIOS/EIFE (and or hardware drivers) malicious payloads.
You can not get completely airgapped device as every machine is subjected to pre-shipment inspection by manufacture that includes the checking its connectivity to Internet.