Yes yes, all your friends are rich, good for you.

4k displays are available at just a few hundred bucks these days, I'd hardly call that being rich.

That was absolutely not true in the "early 2010s", not even 5 years ago unless you wanted to seriously compromise on some other aspect of the display.

I did not say people used 4k displays in early 2010s en masse, I said that's when I last saw people use 1440p displays. I live in present time, and in present time 4k displays are very cheap. It gets a little more pricey if you want high refresh rate as well, though my 4k 144hz display was just around 400 EUR, which I would consider a lower-mid-tier price range.

You are misremembering things. Macbooks in early 2010 had only 800 rows of pixels: https://support.apple.com/en-us/111958

Great sample size