Again, like with the phone, I would always need to take it out the pocket. Which is inconvenient if the pants are in the bedroom but I am not. Or I have a different pair of pants and the contents of the pockets hasn't got swapped.

Ah. I actually leave my Yubikeys plugged into my computers.

I use the Yubikey Nano. I have a USB-C version in my laptop and a standard USB version in my desktop PC.