Why did 1080P HDTVs come about? Because CEMs could charge more for them. Not 500% more - just 35% more. And the public didn't embrace "Full HD" until prices came down A LOT. Yet even today, they still buy plenty of 720P (or 768P) HDTVs.
The USA spent 8 years getting the HDTV standard set in place. It started in 1990 and the first OTA broadcasts were in 1998. It was always the intention to use HDTV as the next television standard. That is not the case with 4K.
4k + OLED would be sick.