If hardware wallets became unusable, would confidence in Bitcoin weaken, or would people adapt with new storage methods? Is this even a possibility ?
No, why would it weaken Bitcoin when everything is stored in the blockchain?
A hardware wallet is just there to protect our Bitcoin from online attacks, and so it's not like our Bitcoin is stored on that physical device. And you to backup your private keys and mnemonic phrase that you can used to restore your Bitcoin if ever your hardware wallet "suddenly stopped working".