Bezos can hire engineers to work for him. Amazon requires lots of engineers and that works fine.
Bezos’s big contributions will be leadership, creating efficient processes, etc. He’s good at those things. You don’t need to be able to build the product to run a company.
Then why hasn't he done so earlier?
Sure, he studied electrical engineering in the 80s, but I don't think that's going to help Blue Origin catch up with it's main competitor.