Why did they not bring them back

Kys super spic

Toriyama forgot about them even though they're important to the story.

Raditz doesn't want to repent for his sins and will most likely join Frieza's forces to work his way up motivated by a desire to surpass Goku.

Nappa is better than the two in that he's given a chance to come back to life in FighterZ, but nobody wants to address the fact that he's angry at Vegeta for killing him after years of loyalty. As seen in the game, he's proud of being a mid-level solider since the Earth raise Saiyans have gone soft.

go reread that part in the manga, it's specifically shown that they're not revived because Vegeta killed them.

>Vegeta
>Having friends
Pick one

Nappa is explicitly written as a soldier who uses brute force to solve his problems and loyal to Vegeta. His only flaw is lack of focus.

I like Vegeta's dynamic with Nappa and Raditz more than Goku. They bring out his smart points and ruthlessness, while Goku's friends irritate him.