The key there is "vast majority of tech companies". And I agree with you.

I think the next big movement in tech will be ALL companies becoming tech companies. Right now there are hundreds of thousands of "small" companies with big enough budgets to pay for a CTO to modernize their stack and lead them into the 21st century.

The problem is they don't know they have this problem and so they aren't actively hiring for a CTO. You've got to go find them and insert yourself as the solution.