Except also energy constraints.

But I agree, there’s no reason to believe humans are the universal limit on cognitive abilities

The energy constraints for chips are more about heat dissipation. But we can pump a lot more energy through them per unit volume than through the human brain.

Especially if you are willing to pay a lot for active cooling with eg liquid helium.

A constraint is still a constraint

A constraint that's not binding might as well not exist.

Since we do not know what cognition is we are all whistling in the dark.

Energy may be a constraint, it may not. What we do not know is likely to matter more than what we do