Teachers will be more plentiful and better educated if you pay them a salary >100K and select rigorously.

Only to a degree. For example, a nation without decent lawyers or engineers could never become wealthy. Or, in other words, a nation of 100% illiterate people won't be as wealthy as a nation of 100% PhD, which shows that education is about more than just relative position within the population.

The question is: are VR headsets going to significantly better at education than say, a book?

That question is way too broad to be answerable. VR won't be better at teaching you about writing than a book. If you want to teach biology or woodworking VR can be significantly better than a book.

I'm pretty skeptical of that. Books are great at teaching kids to solve integrals and write essays. I haven't seen any evidence to indicate that VR headsets would help with these skills.

VR is just a medium. Why would it not be just as capable at teaching kids to solve integrals and write essays? You may argue that it can't possibly do any better of a job than a book could, but I think it's unlikely that there is anything a book could teach you that a VR headset could not also teach you. After all, you could just digitize the book and read it in VR.

Also, it doesn't matter how good books are at teaching kids to solve integrals if 90% of them won't even give the book a chance, but can't wait to get on their headsets.