It's my opinion that taxpayers are the worst people to drive business decisions around education. The median tax payer will only care about education quality and availability for around 15 of their ~40 years as a tax payer.
For those remaining 25 years, they will tend to prioritize money in their pockets over a teacher's salary; a situation that does not align with the betterment of our society at large.
A million dollar teacher won't be able to do their job effectively if the child lives in a broken environment, so it's something that has to be attacked from all angles simultaneously, from the teachers, to providing the child's parents (and neighbors) with economic opportunities (and/or educating them), and even then it would be a slow process taking effect over generations, so no politician could claim it. Seems almost impossible to accomplish in a democracy.
There are plenty of million dollar teachers, but they work in private tutoring or corporate education positions.
The million dollar teachers will do things like actively manage the student's home life or business trajectory, give them personalized curricula, connect them with opportunities to gain hands-on experience, etc.
Not saying you're wrong re: the incentives or anything, but a lot of people don't even know this segment of the market exists.
The purchasers (taxpayers) are not willing to pay sufficient wages in order to incentivize [the right] people to pursue it as a career.