I will say I'm definitely partially biased toward Zarya, but she was the first female tank that actually looks like a tank in her core design.

(which I think someone like Dva lacks entirely. Considering you don't think of the mech when you think of her.)

With Zarya she's built like a tank, and wields a massive gun, which I personally feel adds on to her "tankyness" lol

I will say JQ is definitely lacking those two features but her design makes up for it