The more general model of "local password that unlocks a key" seems like better security at every turn, and something that's feasible to implement on any system

The more general model of "local password that unlocks a key" seems like better security at every turn, and something that's feasible to implement on any system. This leaves attackers with the same options they'd have with 2FA: Gain access to the device that produces/stores the key, or crack the crypto. There's no technical feasibility concern for implementing good security, there's just endless incentives for these big players to pretend it's hard without you handing over control