.. Perhaps it is more theoretical or both. I was thinking about the fuss over 4k gaming and the extra pixel magic it supposedly brings.
Question: If you have a comparable level of PPI with 2k Are you actually getting anymore real world detail or just a bigger potential screen by using 4k ?
Question 2: If the game is not made for 4k then will you get any more detail on a 4k screen vs a 2k screen with comparable PPI to 4k even though there is technically more pixels on 4k ?
Okay, now here is the odd bit..
Question 3: If the game IS made for 4k and played on a 2k screen with adequate PPI comparable to 4k. In what instance are you actually viewing a single 8mpixel texture in full on a 8mpixel screen. There is only 1 x 4k full field resolution per frame for the canvas ( if that makes sense ) so at distance within a 3D plane your scaling 4k textures in and out of the field of view, which means your never seeing 100x 4k textures in full your seeing scaled versions of that texture, at what point does PPI meet scaling.
So, PPI vs texture scaling within a 3D plane. Is a 4k ready game @2k with comparable PPI to a 4k screen going to look any different ?
I am not 100% but I will stab question 1 with a sharp thing as is the nature of these questions.
I game on an iPad screen. A 9.7 inch 2048*1546 screen, about a half million short of 1440p and at a quite high denstiy. The other thing to take into account is distance. A real iPad will be hand held and a lot closer to your face, mine being a monitor is on a desk behind keyboards and a usual distance away from me as you would imaging desk stuff would be. This actually has the effect of further "improving" the image as the further away you are the easier it is to resolve the image or get to the point where you cannot pick out individual pixels any more and are effectively looking at a live moving picture like looking out your window.
So with that in mind. Yes a lower resolution than 4k but at equal or higher PPI will absolutely result in as sharp a picture.
The down side to get that you either have to a) have a large monitor at lower resolution and sit farther away to resolve it completely or b) sit at your normal disrance from a monitor but use a much smaller screen.
I no longer run AA in games 90% of the time because it is just not needed any more.
That is an aweful answer I may have even gotten the question worng, if you want something cleared up let me know and I will try harder to explain.