Well because of that approach NASA lost the ability to do human space flight. They literally couldn't do it, and the admired that they basically can't develop

Well because of that approach NASA lost the ability to do human space flight. They literally couldn't do it, and the admired that they basically can't develop it internally without it costing 10s of billions. So that's why the used the Commercial Crew program and that worked out for them. The SLS is a good example, 10+ years of building at a cost far above 20+ billion until the first launch.