Instead, we as an industry prefer to adopt magical thinking where we pretend that software projects aren't hard and lengthy and risky (even when the domain and tech are well understood), then we act surprised when the project "overruns".
I can only speak from my own experience, but every single web application I've worked on has had a wildly different structure than the others and the only consistent thing between them has been endpoint routing mechanisms.
If the business is a relatively generic e-commerce store, it should usually not be building bespoke e-commerce software. Unless, of course, there is some technology feature that will be your competitive advantage/differentiator. But let's be honest, that's pretty damn rare in the space of e-commerce stores.
I'm mostly just saying if the author is able to sell what amounts to half a broken Woocommerce installation for half a million dollars (assuming it's at least a team of two billed at $20/hr), I must be in the wrong market.