Yes for various things, but not when self-custodial action is the goal. 

not always something with closed code means something worse, often such a technique is used to prevent various attacks

momboteq

Yeah there was that, and the email exploit, now the recent recovery scheme. They've innovated in ways and done things that the industry has copied, but for me its the closed-source thing which in this space immediately signals *bad actor*

mallardshead

bitcoin

Best cheap hardware wallet

Ledger is a fairly popular and proven hardware wallet. Of course, there was an affair some time ago with the Ledger Nano X and the extraction of keys from the device🤣