The point of the airgap is to reduce the likelihood your seed leaks during signing.
The alternative is to plug the device into the machine (USB) or have it communicate over some other channel (BlueTooth, camera + QR codes).
Airgapped with PSBT or QR is the least leaky available option. But again, the point is to protect the seed during signing.
Not to generate seeds. Not to protect data at rest.
