There was a study during the 2016 elections that showed that over every successive election, the percentage of policy questions had reduced with moderators in debates asking more personality questions. The trend really spiked in 2016 with Clinton being bombarded with “but her emails” questions. It might have fallen to 20% policy questions.
Further, Vox wrote a 2016 article that showed that even on these questions Trump and Clinton spent only half the time actually answering the question.
We are in an in era where we expect candidates to answer gibberish to questions unrelated to job experience. Thus, it’s not unsurprising that candidates are uninformed and unprepared.