So I agree with you. But if one doesn't know how to go about centering a rim or where to read up on it and to absorb the lessons, at that moment one does not have the needed expertise. If one has the inherent skill to try it and learn from the effort and mistakes and get through it with some success, one has learned a few things.

"Expert" is a relative term. I'm not a professional wheel builder, but when I get a new-to-me wheel I check if it is true, is dished and has even tension tension and I work methodically to improve some of the problems I find. Am I a real expert? Not compared to a person in Doug Fattic's class. Do I have some expertise? Yes.

Is it enough that folks are motivated to pay me for my golden words? Not so far!

What about for cold-setting? I have several frames that have been cold-set, done by local professionals, cep for the one done by Ron Boi. I don't have his skills and knowledge, he's up there with Doug Fattic. I can take a set of H-wrenches and check my dropout alignment, and to use a string test to check rear-triangle matching, and I can use a derailleur alignment gauge. Expert? No. Able to work capably in a limited capacity on frames? Yes.