It's more than that. The way black box composition is done in modern software, your n=100 code (say, a component) gets reused into a another thing somewhere above, and now you're being iterated through m=100 times. Oops, now n=10k

Generally, Casey seems to preach holistic thinking, finding the right mental model and just write the most straightforward code (which is harder than it looks; people get distracted in the gigantic state space of solutions all the time). However this requires 1. a small team of 2. good engineers. Folks argue that this isn't always feasible, which is true, but the point of these presentations is to spread the coding patterns & knowledge to train the next gen of engineers to be more aware of these issues and work toward said smaller team & better engineers direction, knowing that we might never reach it. Most modern patterns (and org structures) don't incentivize these 2 qualities.