Without understanding how it’s built, how do I know if there’s duplication, dead code, or poor patterns? I used to obsess over this. Now I’m less worried that a human needs to read the code, because I’m genuinely not sure that they do.

What you do need: simple entry points, explicit code with fewer abstractions, minimal coupling, and linear control flow.

Seems to be the common simple standard software works well fallacy.

By “can replace developers”, what do they mean? They don't clarify, only talk about their three success projects.

We've seen studies of the issues and risks, and discrepancy between user perception and more factual gains. And this post certainly seems like they're not experienced in or thinking of development and maintenance that goes beyond simple standard integration software. Which doesn't make it too surprising they're not concerned about security for those simpler projects either.