One thing that always bothers me about UVI products is iLok. And I suspect I'm not alone in this. NI and U-He have their own license/activation tech which is way more user friendly.
I also suspect big developers like Spitfire, OT, etc, would not risk investing tons of cash into Falcon products when Kontakt is already the de facto standard. Falcon might be more powerful with the IRCAM stuff, but other than Kontakt's ancient UI it does the job well for samples.
So basically the only company investing heavily into Falcon is obviously UVI themselves but their stuff doesn't have universal appeal tbh. There are also a couple of small companies and sound designers like Simon Stockhausen but that's not enough to shift the market away from Kontakt.
IMO UVI should make an aggressive push to increase adoption of Falcon. Maybe reaching to companies with an ample Kontakt catalog like say Cinesamples and offering to port their stuff to Falcon for free. I don't know, maybe UVI is just doing fine and doesn't care for more adoption.