With one exception, every split key you can buy or make right now is a product of the mechanical keyboard community's enthusiasm. I'm referring to the Kinesis Advantage of course, which is a wonderful device but not my choice.
So yeah, there's a whole subsection in the hobby which makes like 30 key hello-kitty-themed clickbait (look maybe someone actually uses the really minimalist layouts but I roll to doubt), and I don't begrudge them at all, because it's the same hobby that develops things like the Dactyl Manuform, which is going to be my next keyboard some time after I get my filament printer set up in my new home.
In other words, if you think sourcing split mechanical keyboards is hard now, you should have tried to do it before the mechanical keyboard hobby invented them.
Are you high? There are plenty of split keyboards that have nothing to do with mechanical keyboard community unless your think mechanical keyboard community has been active since the 1920s
Wouldn't increased demand (regardless of purchase motive) increase supply and decrease the price?
Occasionally there's some innovation and slowly we're seeing some of these innovations from individual designers get copied by companies more capable (and more importantly, willing) to mass produce things.
Ding! Ding! Ding! We have a winner!
Mechanical keyboard communities are 110% all about aesthetics. For most it is far more important how the keyboard looks than anything else, the comes how it feels and sounds and somewhere very far comes actual functionality and even further ergonomics.
Obviously there is nothing wrong with this, but it makes sourcing split mechanical keyboards hard and expensive.