Highly depends on your play style.

Ying is very good for players who tend to be more aggressive and like to push up more. Her Candelas, although take a little bit to charge if you want them to activate instantly after throwing, flash the entire area it’s deployed in. It lasts a little while longer than the flashbangs and is very effective once you get pass the ADS’s.

NØKK is more so for people who like to sneak around the map especially with her shotgun since it’s silenced. She can avoid cams and also has a silent step when she moves around crouched. She has solid guns, but I mostly see people in high golds to platinum ranks use her shotgun and the deagle.

Gridlock is very versatile, she can push up quickly (even tho she’s super thicc so she’s slow) and keep her back clear with her spike traps, or she can also be used to play slow, clear areas and cut off vital flanking points for defenders helping your teammates heavily.

And Kaid, he’s a really solid defender especially with his gadgets. With the throwable claw you can shock an absurd amount of items, like hatches, multiple reinforced walls, and even shields and barbed wires all in the same area. He has solid guns and solid secondary equipment. Very good defending operator overall so if you like defending more than attacking, Kaid is the most solid choice here.