Excellent question and observation!!!
At one time or another I have been in clubs in N, HO, 2 rail O, 3 rail O, live steam 1" and 1-1/2" (same club), and full size. I have a little bit of G stashed away, but these days I’m exclusively into 3 rail O. I’ve spent a few years working in hobby stores, built models for a living, built a few layouts for money, and had my own train display at the Mall of America. You will find some additional information in my profile.
So what does that leave, Z, TT, and S? Not much call for those these days, though the basic principles still apply.
I like benchwork, trackwork, layout design, electrical, scenery, structures, and operation. I’m not really into steam (though you wouldn’t know it from this topic) nor specific prototypes except for my local area.
You saw a photo of my book shelves in your topic. 55 years of MR in binders, and I’m only 44. More than 30 years NMRA, but I digress.
That’s me, jack of all “trains”, master of none. [swg]
I don’t usually “flash my credentials” like this, but you caught me in a moment of weakness. I hope I didn’t make you sorry for asking.