Emulsions can be screen printed and they look exactly like the screen, textured! BTDT.
Coating film and paper in a quantity large enough to supply even only APUG members is a daunting task, espcially film on 2 supports and in sizes from 35mm to 11x14 or larger and in different varieties.
Paper, ditto, lots of supports and grades.
As for getting support, well Baryta paper is very difficult to make requiring very high pressure rollers to get any sort of glossy surface otherwise it turns out like sandpaper. If you don't get it just right, the emulsion you coat on it will turn black in spots due to imperfections. Even the photograde baryta paper I buy now has occasional black defects in it, and I would have to custom tune my formula to the paper. At EK, this black dot problem was solved over 50 years ago. (btw, this is not pepper grain and is unrelated)
So, you need a lot of expertise to do it. If you don't believe me, try making up enough 8x10 paper of high quality to last you a week. It takes me about one week to make enough emulsion and coat 2 grades of paper for this.
These 'so called' coating machines above are only able to make one plate at a time and require extensive cleaning between each plate. A production machine has to be designed for continuous running and very little cleanup. Otherwise labor and time skyrocket.
I'm getting tired of this same old argument over and over. If it was so easy, there would be a lot of little companies doing it instead of 3 big ones and other once great ones falling one by one such as Agfa and Ferrania.