Not sure what you're on about... If you want to prove possession of some secret you have to be the only one possessing it. That doesn't work with shared (ie symmetric) keys. Also symmetric keys are not the most used method for auth anyway. Almost anyone uses trapdoor functions for that, to avoid password leaks. Sounds like a straw man argument.
Hardware keys are all about asymmetric cryptography, and are just basically another way to store keys. You still have to manage those keys. It's just way harder, because now it's a physical thing that's much harder to backup/copy by design.
Hardware keys are all about asymmetric cryptography, and are just basically another way to store keys. You still have to manage those keys. It's just way harder, because now it's a physical thing that's much harder to backup/copy by design.