I've also heard that the Google Titan security enclave chip (used in Pixel phones) is very hard to crack. Apple has something similar for Iphones, I believe.
Same. I wonder if my Yubikeys have anything to mitigate this sort of attack. My gut feel says that at their pricepoint and form factor, probably not.
A Yubikey is basically a single chip and a bunch of plastic. At their $50 price point, there's plenty of room for some chip manufacturer to skim off a couple of dollars per chip to add an additional metal layer for a tamper protection mesh, and some other gizmos.