Doesn’t break the algorithm though, you would just have the key and then can use the algorithm (that still works!) to decrypt data.

Also you’re talking about one class of cryptography, the concept of key knowledge varies between algorithms.

My point is an attacker having knowledge of the key is a compromise, not a successful break of the algorithm…

“the attacker beat my ass until I gave them the key”, doesn’t mean people should stop using AES or even RSA, for example.