I think pixel density is a strange metric for a screen you're watching fully (instead of reading text from a part of the screen). If you want a bigger screen you can take the same content and upscale it (early digital cinema showed mainly 2K movies and that was about as sharp as film). These days lots of "4K" blu-ray discs just contain an upscaled 2K movie and most people don't seem to bother.

Also, I don't think the market will ever get to 100" TVs as a norm. You're an outlier: most people have other priorities (don't want TV to dominate the room, don't have room, don't want to pay for the extra energy required etc).