It's like the difference between being fast and quick. AI tools make the developer feel quick but they may not be fast. It's less cognitive effort in some ways. It's an interesting illusion, one that is based on changing emotions from different feedback loops and the effects of how memory forms.
Quickness is a burst; speed is a flow.
Or, "slow is smooth, and smooth is fast"
I’ve heard it that way, which is more memorable. I’ve also heard it this way:
“Slow is smooth, smooth is efficient, and speed is the efficiency of motion.”