This count as air gapped device but why not just invest on a hardwaware that is 100% air gapped like Keystone and Elipal instead of relying on an old PC that has the tendency of being not functional in future? You will need to import your seed phrase once your computer broke so why not invest earlier on much reliable air gapped wallet.
You can use this website
https://wallets.thebitcoinhole.com/ to check hardware wallet specs comparison to easily decide what to buy.
You gave good advice, but I think there is no need to spend money on extra devices. Because air gap devices are just not connected to the outer world, we can do that at home easily. As the OP said, he disconnected all the drivers, which to me does not matter, but he should change the OS or at least re-install it. And you said he should not use some old PC. I think having an old PC is a good thing to make an augmented device.
As there will be no wireless adapters in it, there will also be no Bluetooth, which makes it less vulnerable to the outer world, and the connectivity will be less to the outside world. The device can be used as an air-gap device or an air-gap wallet. But the hardest part is to follow the best practices so that the device remains in the airgap all the time. Because I have seen cases in which people make dumb decisions and connect their device to the internet for some time and think that their device is still airgap while it is not anymore.