> Secondly, it's a lot more convenient to use a device that's always with you than a dedicated standalone single-use computer.

The price the owner pays for this is that they're locked out of their own expensive general-purpose computing device while still having to bear all the inconveniences (babysit OS updates, configure stuff, keep it charged, have the battery fail, buy a new device every five years, etc.)

In the meantime, the standalone chip-and-TAN device costs 30 bucks, is powered by three AAA batteries that hold their charge for five years, lives for 20 years, and never needs a single software update.

I'd choose the small single-purpose device over the enshittified, locked-down smartphone every single time.