Multi-Agent is a snake oil

You dont need a team of humans to write great code - one engineer with solitude and focus is all it takes.

On my own evals I have seen this, though the improvement may not have been worth the extra cost.

The proper way is to use multiple agents for work involving very large context, and splitting the context amongst them. It effectively enables encapsulation and separation of concerns, which yields much clearer benefits when working at scale.