Not too hard.
As example There’s a study from Pennsylvania called who’s teaching the teachers, or thereabouts which walks through some of the issues. Maybe I’ll dig it up when I get to a real computer.
Education majors are the only major where the average GRE scores are lower after 4 years than of the freshman entering the major.
Good Lord, that is almost as scary in some ways as these shootings.
Now, that said, most of the teachers at my daughter's (private) middle school seem to be "better than that". Almost all seem very energetic and engaged, at least in the school setting of parent-teacher conferences, activities, resolving problems, etc. Also, the skills to work with kids are rather different than those to design, say, the landing of a SpaceX booster, or sift through Tax Law.
Then again, my wife formerly taught pre-school and kindergarten at a prestigious school in a 3rd world country, and also was the head of the elementary school (Grades PS-3, IIRC) for a year, and she is unimpressed by the teaching in Kindergarten at even this same private school system our daughter goes to. My wife says if SHE was teaching the kindergarten there, and allowed to use the techniques from her old school, the students would come out at LEAST one grade level higher in reading comprehension, and so on, when they graduated to 1st grade. (I can believe that for a number of reasons to lengthy to discuss, OT, here.)