See and I go the other way. Assuming everything is up front this would be amazing for a teacher based on how OP explained it.
That said, to your point, none of this would even be a discussion if we paid teachers properly and staffed schools adequately.
We are moaning about a technical solution to a problem that already has a solution that has been solved for decades but collectively we choose to ignore that solution because education is a cost centre.
I'll leave the classic Matt Damon bitching about underpaid teachers.