I've always been fascinated by Japanese craftsmanship and aesthetic spirit. It's lovely in so many ways. At the same time, there's an opportunity cost to doing stuff like in "Jiro Dreams of Sushi" where you drill very simple things to absolute perfection, and I wonder under which circumstances this practice is the right approach versus those where it's sub-optimal given modern tradeoffs.
Define "optimal"
once you’ve done this 10,000 times perhaps you will find your answer.
That is a sharp question. You are right about the opportunity cost. As a banker, I look at the "Depreciation Period" (Lifespan) of the project.
If you are building a "Pop-up Store" (a prototype or script), use libraries. Don't waste time on craft. But if you are building a "Shrine" (Core System/Database) that must last for 20 years, "Shugyo" is actually the cheapest option.
Efficiency is cheap now, but expensive later (Technical Debt). Craftsmanship is expensive now, but cheap later (Stability).
We don't need a Jiro to run a fast-food franchise. But we need him to build the Kernel.