Exactly. To me the difference is in scope, familiarity, and stress. While I'm doing the task: 1) Do I have to hold 15 interdependencies in my head? 2) Is this

Exactly. To me the difference is in scope, familiarity, and stress. While I'm doing the task: 1) Do I have to hold 15 interdependencies in my head? 2) Is this something I did a million times in the past and do I already know exactly what the failure modes look like? 3) Is this something high-stress, e.g., is this the big project that's supposed to make my team look good or net me a promotion? Wiring in a UI for a sophisticated CRUD can take 10 hours but it doesn't _really_ have that many interfaces, I've done it a million times, and nobody getes excited about it. It's just something you do. Building a billing pipeline for a product is something I've never done before, is very-high-stakes for the business, and can go wrong in a bazillion ways, many of which are not my fault. There's no way I can imagine getting more than an hour or two of work on this per day.