I've talked to instructors who've just given up. They know the students use AI. More and more of them do every year. The instructors can spot it easily, but if they brought them all into the academic dishonesty process, the department would grind to a halt. So they just let it go. They are all paying tuition, and they'll all get the credential they paid for.
I sympathize with the instructors to an extent, but the reality is that LLMs will be a pervasive part of life going forward. Schools need to completely reinvent their curriculum around that new reality. It's going to be a painful process for instructors accustomed to the old way of teaching.