I only wanted to write down what I learned over the years about high resolutions. So, here we go :)

Technically 4K resolution is a cool thing and delivers impressive image detaills. But practically it's often overkill. The average viewing distance to a TV is 3 meters. The ideal viewing distance is the shortest distance we can reach until we see single pixels. To get the ideal viewing distance for 3 meters in Full HD you would then need a TV with a size of 80 inch. So for 4K resolution the TV would need a size of 160 inch. If your TV is that big lots of people would probably say "Sorry but it's too big". Who wants to sit in the first row in the cinema? Nobody! It would be annoying to move your head to see all the details.

For PC monitors it's a different story. Here people are quite close to the screen. Let's say 70 centimeters for example. Here people would see a difference when they have 4K screens.

It's also a matter which genre people are playing. If you are playing a first person shooter you want to have a good overview of the whole landscape. This means it would be not that good to sit close to your TV because the focus of your eyes would be lost in details. In contrast to this I see racing games especially when you're driving in the cockpit view. In the cockpit perspective you should focus on the street. The inner details of your car are nice but don't need much attention. The cockpit takes much screen area. So you can focus on a smaller part of your screen. Here I think it makes sense to get close to the TV and it's a good example where 4K is fine.

The situation even gets worse with 8K TVs. I understand Sony and Microsoft when they make their next gen consoles ready for 8K. It's not that pracitcal but it's more psychology. It sells better and the press coverage is unfortunately often focused on high resolutions which is a shame. Often there is no discussion about it's usefulness and the press coverage is onesided. If Microsoft would make their next gen console 8K ready but not Sony every kid would say: "Hey, Microsoft has much better graphics".

In order to take full advantage about higher resolutions games also need to have better textures. Remember that time when you could buy the expansion pak for the N64? You can have high resolution graphics but the texture details of the N64 were quite bad. Regarding the limited use cases of high resolutions the game devs should spend the processing power in more detailed environments instead of higher and higer resoutions. Now you understand why I set The Last of Us Remastered to 1080p on my PS4 Pro. I have perfect 60 frames per second and high quality shadows. I could have 1800p with low shadow quality and a target of 60 frames per second but that wouldn't make any sense given my TV size and my viewing distance.

So in the end the question is what use cases do users have for their screens. And dependend on that they should decide which resolution to choose.

To calculate the optimal viewing distances for the different resolutions there is a rule of a thumb. You have to multiply the screen height with a factor. The factor is according to the following list:

PAL: 6
HD: 4.8
Full HD: 3.1
4K: 1.5
8K: 0.75

So for example if we have a 65 inch TV the optimal viewing distince for Full HD is:

Distance = Height x Factor = 0.81 m x 3.1 = 2.5 m

So the optimal viewing distance is 2.5 meters.

(Source: https://abo.video-magazin.de/)