this is delusional hubris from people who are not real engineers. anyone who actually writes high assurance software or does low level performance optimization knows that the only thing that matters is what can be demonstrated in reproducible tests.
the full stack requires about a 1000 different specialties that each require about 10 years of experience to master. and that is just one computer. we are building distributed systems of millions of these computers, operating at global scale, across dozens or hundreds of legal jurisdictions, which takes the complexity of a single computer, and multiplies it many times over, across several other dimensions.
anyone who thinks that they can understand the systemic effects of changing 0.00001% of this system by reading the code is a dangerously naive fool.