Seefree There are two known causes of dithering on that laptop:
1. Intel Graphics drivers
2. Windows 10 Anniversary Build and up
2 is not confirmed, but I think at least one on here is confident it's true. ditherig.exe can get rid of dithering, it helped some people on here, but does not help me.
I hope you can find a laptop that works for you.
Some people have had success using Linux with modesetting (non Intel) drivers on some laptops.