The Problem with Jiren(?)

[ankokudaishogun]

He’s a pretty standard “might makes right” and “friendship is for the weak” stoic anime rival.

So... something that was not really used in the franchise, not for a non-evil character at least.

He doesn’t have any real personality beyond that

Which is pretty much the same lever as everybody else except the long-running characters

, and as I recall, it’s incredibly vague what he even wants the Super Dragon Balls for.

True.
Vegeta suggests it's resurrecting his parents and\or master, but it was not made explicit.
Knowing his desire WOULD help in outline Jiren's personality, and I feel that's a miss of the anime.

The fact that his traumatic backstory is about as generic and cliche as it gets

"Kid gets Double Trauma and ends up FORMING a Superhero team" is not really THAT cliched.

Because something many keep mixing up is that the Pride Troopers were a preexisting team that he joins introduced by his master in the manga, but they were built AROUND Jiren in the anime after the death of his master.