What’s the point of a question like this? “Who pays for teachers” is a policy choice, like it always has been. Whether and how people are willing to pay for effective education vs. ineffective education depends on cultural values and priorities. Does that help?

edit to add: maybe what you’re implicitly asking is “Particularly in America where people view education as an indulgence and a luxury good, how would we ever fit this model into existing starvation-level budgets of the public school system, or into the existing academic institutions which pass all their costs onto students?” This doesn’t change my answer but it makes that answer a little more obvious.

I don't think that anyone seriously disputes that at least some degree of personalized instruction and perhaps hands-on (depending on the subject) is valuable. But it doesn't really scale.

The University of Texas has 51,000 students.

In state tuition and fees are $31,000 per year. Out of state is $42,000.

Maybe we could try taxing the rich?