I was more referring to dragonflies' low neuron count with efficiency, but really efficiency is relative. You're describing speed, or efficiency with respect to time. We're able to do these things faster than a slime mold, but it take a lot more energy. Slime molds can be dropped on the floor and start solving problems, we have to build tools to hunt animals to roast over a fire we've built so we can sleep in a shelter we've built.

I'm just thinking in terms of energy expenditure on the margin. Humans need more energy to sustain themselves, but for a given cognitive task, I imagine they need to expend less energy than slime mold - being able to solve problems by gathering photons and sending electrons down a maze is much more energy-efficient than having to move or grow your body, made of matter, to solve the same problem by touch alone.

That's fair and may. I don't know what the caloric needs of a slime mold are. But this is completely off topic, tbh. The point is that they solve problems in a way that is alien to us, and alien intelligence is interesting. I may have given a poor explanation before, but efficiency is not the important part.