Why do people with gaming laptops play Minecraft in low graphics?

I've seen people in YouTube that have Alienware laptops or Razer Blade laptops and they still play Minecraft in Fast graphics?

I've seen Ali-A, who has an Alienware 17, play Minecraft in Fast graphics.
I've seen SkyDoesMinecraft, who has an Alienware 17 or 18, play with Fast graphics (in some of his videos)

Guest

This is one of the mysteries of the universe, my friend. These people normally play on low graphics because although they have moderately fast gaming laptops, the recording applications they use take up a lot of the CPU… They just put their minecraft in fast graphics to improve the smoothness of the video

Jake