Sorry for the delay in responding to this. Asking what has happened to teaching critical thinking is much like asking if you have stopped beating your dog, kids, or spouse. We didn't really start.
I has an openly stated objective in some twenty-five years of teaching world history to achieve a critical historical consciousness in my students. History, the lie commonly agreed upon, has always been an excellent discipline for teaching the difficulty of critical thinking. One could say, the hopelessness of critical thinking but some people would get the idea.
While I wasn’t alone in stating that objective it wasn’t a crowded field of instructors because there were no totally correct answers. The students who got upset were the ones who wanted the answer that would be on the exam. And there is an example of uncritical thinking.
Without launching into a screed leading to a diatribe, the educational structure is not designed to teach critical thinking. It is designed to groom bureaucrats who perform endless, time consuming rituals with a series of checked boxes as the outcome.
The only thing I can say is that a significant percentage of students now have realized they are on their own. That is both inefficient and scary, but the systems are failing at a high rate and no one wants to look too closely or admit it. So those student’s paths are diverging in ways that may well take them to higher dimensions that can’t even see let alone understand.
We will then need to stay here with the those that can’t get there and provide care.