Until you have something that absolutely, definitely works, let's just teach kids with teachers who are masters of their subject.
That sounds good, but in practice it's not good. Why? To be a master of your subject, you have to live and breathe your subject. To be a good teacher you need to be a bit of a generalist. You can't be so hyper-focused on one thing that everything else in life gets excluded.
I've got an education degree and some teaching experience, and I've also spent a fair bit of time working in and around grad-school STEM programs. The experts in those programs are the shittest teachers, for the most part. Why? They never learned about how kids learn, because they were busy becoming experts. They never learned the basics of assessing learning because they were becoming experts. They never learned motivational strategies because they were hyper-motivated on an exclusive topic, and it never occurred to them that some students need some motivation the way they would for any other topic.
What we need are not masters of their subjects, but communicators and collaborators who can give kids access to people who are masters of their subjects. I once filled that role, connecting NASA scientists to middle school science classrooms. The NASA scientists weren't teachers and didn't know the first thing about it, and the middle school science teachers weren't scientists and engineers. But when we set up the communication and collaboration between the kids and the experts, amazing stuff happened.
That's one thing we need. The other is equitable funding. I think that it's Germany that does the opposite of what the US does. They still have standardized tests, but the results are secret. The lowest performing schools get more money, and the highest performing schools get less. That makes all of the schools roughly the same, and parents don't know which ones are better, so the rich parents can't move their kids out, leaving behind the poor (minority) kids. The US does the opposite - we openly publish our assessment scores, and we threaten to withhold funds from poorly performing schools. Since we also have wacky local funding, parents create these "ghetto schools", as rich parents move their kids to the best performing schools, and work to ensure that they don't need to pay for the schools they left behind. Great for their kids, but terrible for all the other kids. But who cares when you can live in a gated community with a guard to keep the rabble out, right?