The efficiency argument isn't really about macro-efficiency, it's about micro-efficiency. It's not, "with my lightning fast editing speed, I will drop 10k lines today", it's about writing this method faster so I can run tests and see if anything changes, getting me to the next thinking step that much quicker while the problem is still fully loaded into my head. It's about keeping flow state flowing. It's about reducing the iteration time between working code states, so your cycle time gets tightened.