> there is a lot of obviously useful abstraction being missed, wasting lines of code that will all need to be maintained.

This is a human sentiment because we can fairly easily pick up abstractions during reading. AIs have a much harder time with this - they can do it, but it takes up very limited cognitive resources. In contrast, rewriting the entire software for a change is cheap and easy. So to a point, flat and redundant code is actually beneficial for a LLM.

Remember, the code is written primarily for AIs to read and only incidentally for humans to execute :)