The glaring problem is the RTX chip is massive so expensive. Most high end gamers are 1060 or RX580 budget gamers or cheaper cards. Look at the top steam stats for gamers. The top gamers are using budget cards. That includes the consoles.
One of the biggest chips ever built for a GPU will not be tech on a budget card next year or even 2020. Nvidia whole gamble on this chip with redundant tech that is not needed to game is people will pay to play high end.
RTX needs int32 processing and tensor cores for AI. That takes a lot of room on a chip if its not used.
Budget cards will be all FP32 (or with AMD already FP16 at x2 speed).
IF AMD gets into this it will be a multi chiplet thing with navi + (AMD RTX) or just navi +navi chiplet’s ETC. It will not be some massive chip that costs $1200+