Sadly, I understand firsthand what you're up against.
I too, loved the size. I tried my best to be satisfied in S scale in view of the state of the scale. The SHS quality was excellent, AM's quality was good, as were many of the products I was able to find.
Unfortunately, the lack of availability (took me a couple years or so to find only one OMI S-2, I had originally allowed for more than one), the lack of variety (missing key engine types I was wanting to model) and the demand in the secondary market (prices) were what put me back into HO.
Though S is a wonderful size, I was not the type that could deal with the shortcomings in view of my layout and theme goals. Alas, after moving to HO I've never looked back and thoroughly enjoy what I'm doing in HO scale.
100% my feeling. I'm sure it's made worse right now due to a lack of non-internet market - but it's just bad. I'll probably go up rather than down a scale and go with O and go back to dealing with the extra rail. There's at least 3 x 3rd Rail locos I could see running and the Pecos Hudson. Boxcars and Reefers are cheap and plentiful. Such is life.