I'm far from an expert, but it seems like teaching to the test has ruined education in this country.
The problem isn't "teaching to the test" the problem is that to sell a textbook you have to find a buyer. The biggest buyers of textbooks are states -because whatever your textbook teaches, it has to pass a purity test before you get state funding to buy it. The southern states figured out that if they change out their textbooks a lot they get to influence what those textbooks say a lot. The biggest buyer is Texas. So in general, every textbook you find has been approved by the Texas Board of Education. Reactionary, racist, religious shitheels love being on the school board. They know it's how they win the culture war. In 10th grade all our science teachers had to stamp every biology book with a little paragraph about how evolution was a theory and how we were strongly encouraged to learn alternate explanations for the origins of man. Tests? Sure. Same reason. SAT and ACT most definitely been approved by the state board of education.
My gut instinct is that dropping standardized tests with no replacement would be a big improvement in maybe 2/3rds of districts, and public school opponents would burn everything to the ground and salt the earth wherever they could.