you don't have to.
But don't expect great art as a result if you don't have any basic knowledge in art.

You also don't have to practice any fitness if you want to do sport. You can do it without it, but you will simply suck at the sport.

Just because high quality pixel art looks super simple it doesn't mean equally it's super simple to craft.
Just because you only have 8x8 or 16x16 for a char or tile it doesn't mean it would hide your inability to draw, it means that you have to simplify a lot.

Simplification in art comes from deep understanding of the subjects.

It's possible to create something ok looking with pixels with editing and emulating existing sprites, many programmers do this.
although it will be clearly visible that someone who isn't good at drawing does it.
And this pixelart sucks and it's what people mean if they talk of "another cheap pixelart game".

I got it, thanks.

I will try to learn the basics of art first, since I need learn how to do high quality sprites.

A friend of my recommended me the "keys to drawing" from Bert Dodson, I'll give it a try.