How do you enter the passphrase when it has just one button? Or is it scanned in through a second QR code? Of course this wouldn't be an acceptable solution either, since someone could take a photo of that (while you don't notice) or just steal it, as well.
Dude, I don't know who told you about one button, but you are wrong about this, it would be almost impossible to operate any device with just one button, unless it's joystick style 
Small device M5StickV K210 have two buttons I think, and other larger devices that work with Krux code have more buttons.
Sure! But at that point, it resembles more an airgapped computer than a hardware wallet, for me. Of course it will be hard to draw a line between the two definitions.
It's airgapped device.Computer usually have more functions and it has wider attack surface.
You are referring to this attack, right? https://hackaday.com/2022/11/26/defeating-a-cryptoprocessor-with-laser-beams/
Yes I was talking about this, but previous version of secure element ATECC508A had even bigger issues, so old ColdCard (I think mk2) had to change it very fast.It's realistic to say that same thing can happen with ATECC608A and ATECC508B in future, like with any other secure elements, and you can't exactly remove and replace secure element from working device.
Do you know how passphrase entry is realized? I believe unless you have a nice keypad like Passport or ColdCard, most people will just avoid using (a sufficiently secure) one.
Even if you have perfect keypad like Passport you certainly wont write very long passphrase essays, because you still need to enter this each time you are making transaction.