Chromatizm
Power User
I think I know what you mean and I (mostly) agree with you.I don't agree that he's "missing" anything...
If you don't need those controls they do nothing for you.
It is my experience though that without them I wouldn't be able to use some of the amps I love now, they are just not exactly "there" to me - until I open Ideal page and/or some other favorite parameters in the Amp block.
Same for Cab block - you don't need Preamp page, but once you get a taste of it, you are never coming back.
It's not only Amp, it's also guitar/pickups, fingers, speakers, etc. - Advanced pages allow you to make the final adjustments to get "there" every time with almost any amp.