Most computers do. All laptops and most desktops have an integrated GPU on the CPU.

That's the first. Do you have sources most have more?

He’s right. Laptops have integrated graphics, but all mid-tier and higher laptops also have a dedicated GPU. Desktops are similar, though my guess is a lot of business desktops have only the integrated graphics.

As I mentioned, can be done with a single GPU as well, just makes it a bit more complicated to set up.