Nvidia isn't a monopolist. They have two big competitors in AMD and Intel.

Intel ship about 2/3 of the graphics chips for laptops and desktops. Nvidia have more than half of the remainder. That isn't a monopoly.

In the discrete GPU space AMD are also there and ship almost half as many unit as Nvidia. That's no monopoly.

The graphics systems for the current consoles are shipped by AMD aren't they?

Nvidia is a profitable company. Calling them a monopolist because they are profitable is unwarranted.

* Edited to fix grammar.