It's still kinda early in the 4k game.
Discs are expensive. Most don't have the player or displays for it.
And even though I have a JVC PJ (1080p), I'm sitting 1.5x screen widths back, which I kinda like. pixelation is not an issue for me.
When the SOURCE is amazing, 1080p is amazing. To me, 1080p as a standard is pretty damn good, unless I want to sit real close to a big screen.
It's the other things, HDR, etc. that add up to a noticeable improvement.
I'm sure I'll 4k someday, but as a resolution only question, I can't see the pixels on my 80" screen unless my nose is a few inches away...