Of course, there are different domains of intelligence, and agent A can be more intelligent in domain X while agent B is more intelligent in domain Y.

If you want to make some comparison of general intelligence, you have to start thinking of some weighted average of all possible domains.

One possible shortcut here is the meta domain of tool use. ChatGPT could theoretically make more use of a calculator (say, via always calling a calculator API when it wants to do math, instead of trying to do it by itself) than a calculator can make use of ChatGPT, so that makes ChatGPT by definition smarter than a calculator, cause it can achieve the same goals the calculator can just by using it, and more.

That's really most of humans' intelligence edge for now: seems like more and more, for any given skill, there's a machine or a program that can do it better than any human ever could. Where humans excel is our ability to employ those super human tools in the aid of achieving regular human goals. So when some AI system gets super-human-ly good at using tools which are better than itself in particular domains for its own goals, I think that's when things are going to get really weird.