[tiltowait]

That tracks with my experience. There's just not much in the full ergo market (though there's plenty in the faux-ergo market ...), so once you find one you like, there's very little compelling you to switch.

It's an incredibly fad-driven market, and full ergo is "weird enough" that it doesn't have nearly as much widespread appeal (despite being inarguably superior for preventing RSI).