I went to what I assume was a fairly typical U.S. public school (if maybe a little smaller than average) and, sure, I had some teachers I liked better than others, but I don't think any of them made any difference. (And remember, the argument here isn't that the player on the field never caught a popup; it's that they didn't do it any better than any other random person could have.)
In fact, since my town was pretty small, I actually started kindergarten with a lot of the same people I graduated high school with, so I knew these people across their entire primary and secondary educational experiences. And, basically, things more or less shook out exactly how you could have predicted if you'd just have given my entire kindergarten class IQ tests and pre-registered SAT/ACT scores on that one data point.
Yeah I went to public school in San Francisco and the consensus among my friends (in high school) was that fully half our teachers were quite literally insane. Like "should be in an institution (not a school)" crazy.
We felt that the fact that the adults in the situation (parents, teachers, the PTA, the school admin, the Education System up to the Board of Education, and society en mass didn't do something about this, that instead our teachers were half of a insane asylum, really put a damper on our enthusiasm for the whole thing.
That’s just evidence that relative performance within a group is not affected when the entire group goes through roughly the same experiences. This is obviously true and is completely orthogonal to “the individual teachers don’t matter.”
That would be true except that we see the same thing across school districts. (There’s no evidence that teacher ability predicts district-level outcomes, either.)
What kind of childhood did you have!?
(Are you just trolling? If so, bravo! You got me!)