I have a theory that native 720p/768p panels are going to go up in value on the second hand market once they're no longer available. xbox 360/ps3 era games don't look quite right scaled up to higher resolutions (and a lot of stuff from the generation afterwards too). The retro gamers with cash burning a hole in their pocket are going to get to that generation soon and won't have nostalgia for old CRTs anymore.

I bet you could do pretty convincing 3x scaling on a 4k oled and simulate the individual R, G, and B pixels with the right hardware though.