If you're building something yourself or in a small team, I absolutely agree with everything written in the post. In fact, I'd emphasize you should lean into this sort of quick and dirty development methodology in such a context, because this is the strength of small scale development. Done correctly it will have you running circles around larger operations. Bugs are almost always easy to fix later for a small team or solo dev operation as you can expect everyone involved to have a nearly perfect mental model of the entire project, and the code itself will regardless of the messes you make tend to keep relatively simple due to Conway's law.
In larger development projects, fixing bugs and especially architectural mistakes is exponentially more expensive as code understanding is piecemeal, the architecture is inevitably nightmarishly complex (Conway again), and large scale refactoring means locking down parts of the code base so that dozens to hundreds of people can't do anything (which means it basically never happens). In such a setting the overarching focus is and should be on correctness at all steps. The economies of scale will still move things forward at an acceptable pace, even if individual developers aren't particularly productive working in such a fashion.