This is very true and as an educator I agree with you. While not many studies have been conducted on blockchain and education, there are many private entities who have started this this. Very soon, we will see a revolution in the way we teach.
However, the way Blockchain can be implemented is fairly limited. A decentralized classroom can only be implemented if all the students are motivated. It does work for older students, but that may not be the case for younger students. We may see less teachers and less classrooms in the future, but we will definitely see more education coaches who will motivate these students towards learning.
I have talked about education and the blockchain here and I am also one of the contributors on one of the education projects on the blockchain.
What they are doing is very similar to what you have mentioned, do check them out!