A lot of teens and some early twenty-somethings can be a bit conversationally shallow, due to not having fully developed social skills or lacking more than the most basic knowledge about some subjects… or because they find engaging in brainrot on purpose fun, for whatever reason. Not all of them do, and most of them grow out of it, eventually. It’s rather unfair, and at least a little dehumanizing, to equate them with NPCs or chatbots.
I suspect this goes a bit further than that. People with Main Character Energy™ often see conversations which hold no interest to them as superficial. Because if it doesn’t matter to them, then it’s an unimportant waste of time. Given the pop-cultural disconnect between the older and younger generations, as has always been thus, it can contribute to the whole “young people in particular are weird and shallow” attitude which people like this often have.