I like your analysis. That decision between buy or build is a very hard one. As developers, I believe we are always inclined to develop ourselves. However, we need to start focusing on speed of innovation, and sometimes that means, buy instead of build.
I like the perspective C, let’s be practical or maybe something along the lines of good enough IT. If you shoot for perfection, you might never actually reach your target.
For me, I believe you need to design thinking about perfection but prioritizing the practical aspects. Nonetheless, keeping in mind that end goal of perfection is important to minimize the technical debt.