I’m not going to proclaim my normative answer to that question.
I will, however, note that a lot of people claiming to be superusers, are not actually that super. As in: I reject your claim to superuser status in Excel, if you sum a column of 1s in order to count how many rows your data encompas.
This site tries to provide a classification. It is made by Aaron Blood. He is a “Microsoft Most Valuable Professional”. I have worked with Excel on and off for the last 25 years. I have only just moved from “Intermediate” to “Advanced”.
Personally I think this scale is not granular enough. The step between “Intermediate” og “Advanced” is rather large. But I think the scale is useful because it illustrates what Excel actually can. The average “superuser” do not even know that macros is an option. And that makes it entirely reasonable for them to claim that they are superusers. They know everything that they know there is to know. They think that what they know is the entirety of what Excel can. They have no idea how much more there is to know.