I’ll believe it when coding agents can actually make concise & reusable code instead of reimplementing 10 slightly-different versions of the same basic thing on every run (this is not a rant, I would love for agents to stop doing that, and I know how to make them - with proper AGENTS.md that serves as a table of contents for where stuff is - but my point is that as a human I don’t need this and yet they still do for now).
In my experience they can definitely write concise and reusable code. You just need to say to them “write concise and reusable code.” Works well for Codex, Claude, etc.