I don't think it's because of the 'average developer', but because system's like OP's were designed by experienced engineers, while the modern toolchain is written by "senior developers" with 3 years of experience. They have a lot of energy to pull all-nighters reinventing yet another wheel, and not the wisdom to avoid doing that, or to do it in a sensible way.

In fact, the entire tech sector, favouring fresh grads out of college over greybeards, is built this way. My pet very controversial theory is that this phenomenon is massively fueled by everybody and their dog using ADHD stimulant medication to get through their day; fresh grads + amphetamines is the preceding step to Kubernetes and the entire React ecosystem.

tl;dr: modern software is built by 'work hard, not smart' kinda types.