You wouldn't need anything like 4000x3000 for 'retinal indifference' using the article's number of 287ppi@12" use distance as a basis for that threshold. 4000x3000 pixels, assuming a 22" screen is about 227ppi. The threshold in the article, translated to a typical working distance for a laptop of 22" is about 156ppi. So a 22" diagonal screen (same aspect ratio as your 4kx3k) would only need 1850 pixels on the short side to hit the 'retinal indifference' number.
Oh, and some other smartphones crossed into retinal indifference at their typical use distance sometime late last year.
Oh, and some other smartphones crossed into retinal indifference at their typical use distance sometime late last year.