She can deal 180 dps to shields and tanks after standing there for nearly 3 seconds.
Tracer can deal 240 dps to shields, and potentially 480 dps to tanks.
Soldier 76 can deal 171 dps to shields and potentially 342 dps to tanks.
Neither of them require standing there for nearly 3 seconds to reach that damage. Sure, maybe Sym is better at destroying sheilds because she doesn’t have to reload. But, there’s not that much of a difference between them. And, if Bastion is ever in a viable state, this ‘tank-busting’ niche that Sym has will be easily outshined.
And in doing so, you have to place at least 1 of your 3 turrets away from the the rest of your turrets, which will easily be destroyed.
Unless you want to place all 3 of them somewhere on the off-chance that they pass by.
Also, I’m confused why you missed out Wrecking ball, because he’s heavily countered by her turrets.
Her wall isn’t enough for her to be a justifiable counter to pirate ship over the likes of someone like Sombra.
Roadhog can literally burn through her shield.
Genji’s way to mobile to allow you to consistently track him. That combined with having to charge up your beam, and it’s way too hard for her to be anything close to a Genji counter.