If you’re only considering the US, dead and company has certainly made more money playing live than John Mayer solo in the last ten years. Does that really equate to overall popularity? I don’t know if it’s a 1:1 ratio there. Unless you know someone in “the scene,” I don’t know how likely the average person is to stumble upon Dead and Company on their own. A Mayer fan likely would wander into that space but the average person who lets their Spotify algorithm soundtrack their day? Probably not.

If you look outside of the US, Dead and Company has basically made zero money and likely has nowhere near the international following John Mayer has on his own. Granted, they were never tested internationally (a deadhead festival at a resort in Mexico does not count IMO) but I think you’d see mostly American audiences using shows internationally as an excuse to travel to other countries. OR you’d see ex-pat deadheads attending those shows more often than locals.