Software is very hard to do well, and you're right that many in-sourced projects fail or suffer extensive problems. But when you outsource, you keep all the normal, natural problems of software development and add many more enormous burdens and difficulties on top of that. In my experience, the failure rate of outsourced projects is much higher than that of in-sourced projects. We can't gloss over the differences by just saying that they both experience failures.

I agree that capable engineers are very important, but I have seen more than one project with high-quality engineers fail. Of course, you very rarely get high-quality engineers with outsourcing.