Neat thread....and glad t see you venturing into minis.
As an aside, I am a model railroader from many years back
Kids in the 1950-60's ran O-scale trains (my brother included). This is 1:48 scale. These are what most folks think of when they think model trains...and usually what you see under Christmas trees. There's a sunset of this called, On30, which is basically the same size, but the rails are closer together.
But people had issues with these big trains, so HO-scale came along....that's the scale I run. This is 1:87.1 scale. Smaller trains allow more room to run. This is pretty much the dominant scale these days, hence your probably seeing more of this scale in the stores you frequent.
There's a big movement these days in N-scale, of which you talk here. This is 1:160 scale. These offer the most room to run a huge layout in a small space....but it is still a specialty run, hence, not as much out on shelves, but plenty online.
There's my two cents