“But the (teachers) union has nothing to do with how the core subjects are being watered down.”
Are you smoking something?
I taught in urban public high schools for decades. And I never once saw a teachers union influence a course of study. Never once. Those decisions were always made by the school board.
Before around the year 2000 a committee of teachers would work out a curriculum, then forward their proposal to the board. I myself served on a number of chemistry committees. But we could only suggest. The board always had the final say.
Today the courses of study are usually not picked by teachers, but by outside “educational consultants”. These folks are university types who know nothing about urban education. And many are social justice warriors. Most of their (stupid) suggestions are rubber-stamped by the school board.
The union is simply not involved in any of this. Some union leader might offer a personal opinion. But it carried very little weight. Trust me on that.
Now don’t get me wrong. Teachers unions dabble in politics. And they almost always support far-left candidates. I found that to be infuriating. But that’s another story.