So I've never gotten a satisfactory answer as to why there aren't interesting niche phones that don't sell a ton (anymore: android used to be full of them, that was half the point), but are enough for a small company to make consistent (but small) profits. People who want niche phones are a tiny fraction of the market....but the smartphone market is enormous. A tiny fraction seems like it should be able to sustain a few small companies.

My best guess is that the kind of person who would found a company capable of making such a phone won't do it because they know it doesn't have potential to make them fabulously wealthy (just regular old wealthy) because it's inherently limited in scale. And the big companies don't do it because, while such a line could be profitable, in the absence of competition, it's more profitable to force their consumers to buy the "main" line and not make another product line.