MONEY MONEY MONEY
build your own? MONEY
use a middle? LESS MONEY
Would you consider Shin 'en a super rich game developer? Probably not, but they write all of their own engines. Bare metal programming does cost at first to acquire talented programmers, but it pays dividends in quality and polish if used properly. That's not to say there is something wrong with using the development environment tools to make certain processes faster, it certainly helps and can provide a higher standard of quality.