2 Linux phone companies in active development, with 4 phones between them. (Librem 5, PP, PP+, and PPP) Plus there are the Planet Computer products which can run Linux as well. Gemini and Cosmo are two of their product available now, and the Astro Slider just went into production and will start shipping soon. While it runs Android now, as with their other products they are promising that eventually it will be able to run Linux.
So yeah, today there are more Linux phones than ever before. It seems a bit crowded to me.
Plus out of all of them Purism is the only one actually developing the software to work on mobile. So lots of hardware, but not a lot of software work.
Creating a working cellphone is a massive amount of work, ESPECIALLY if you don’t want to use any of the already established code bases and firmwares. Then the takes becomes nearly impossible. This is why Purism is taking so very long to complete all of their Librem 5 goals.