Frankly I don't think we are THAT far off from having a decent replacement for CRT, at least as far as most people are going to notice.
All I want is a high contrast monitor with a high enough resolution to make HLSL scanline scaling artifacts unnoticeable and high enough refresh to likewise make tearing issues unnoticeable. If a 4K 240HZ OLED monitor came out tomorrow cheap enough I'd have no issue using one of those in a machine.
OLED have lag like LCD (retina retention), some panel makers are adding "black frame insertion" to resolve this, anyway OLED does not appear to enter the market for totally due to high costs and the difficulty of manufacture, not to mention the rapid aging of the blue component.
The only real alternative is the "ThinCRT" = FED, which by the way is much easier to manufacture than LCD.
I honestly do not think OLED reaches to replace LCD.
As I said, a lot of money has been spent on improving the LCD, so will take a few years to see the FED.
Maybe even if there is a small niche market for the arcade and the retro, it is possible that a manufacturer is dedicated to manufacture CRTs for this market, as happened with vinyls, and until recently with typewriters.