I think a good generalized answer to the question posed is that, as a glut on the market is achieved, demand goes down, and the AR fascination fades, the majority of AR clone manufacturers will also fade into obscurity.
Quite frankly, my military experience with the M16 left me cold to the gun, and I have really never liked them. I have one* (AR15) just to say "I have one," but I really don't like it, and I really have zero interest when all you hear about is this black gun or that black gun and all the ridiculous rails, lights, lasers, butt wipers, can openers etc. that are sold as accessories for them.
Just a theory. YMMV
*I built it and the company that made my lower is already out of business. (Kaiser Defense.)