I’m on that weird boat that actually believes her current kit is not really weak, just severely misunderstood. Just tuning some of her numbers up probably would be enough to make her viable, just like they did with Mei.
But the major issue with Symmetra is that her fame is terrible, because of how underpowered she was at game release (and MANY players still believe some of her past limitations still apply, like “only good for point A defense”), and how easy it was for trolls to use her teleporter to grief her team, making people believe if you are picking Symmetra, you are trying to lure them into a pit. But this is a community issue, not a balance issue. Which is why I think the devs are changing her whole kit, to try to remove that perception from the community. And IMO, unless she gets overtuned to Valkyrie 1.0 levels of broken, I doubt that will be the case.
The only thing in Sanjay that is “more usefulness for the team” is the new teleporter. Everything else is pretty much “more damage”.
And the main problem I have with that approach is that I don’t see Symmetra’s character as a primary damage dealer. Alongside Mei and Mercy, she is the closest you have to a “civilian hero”, someone that have some special ability/weapon, but don’t focus that into battle as its primary use. Mercy character is about healing people hurt by the war. Mei is about fighting climate changes, and her short reveals she uses her weapon as a utility tool, not a killing tool. Symmetra focus her efforts into building a brighter future for everyone, and her comic reveals she is not found of the idea of killing people (unlike, Eg, Reinhardt or Junkrat show in their comics).
I can see she using her current beam as self-defense, and I can even see she “trying her best to not kill unless absolutely necessary”, with its ramp-up mechanics. Add to that the fact that the orb (which she used in the comic to STUN) is a better tool for 90% of the match, and the beam limited range, it plays within her lore. Giving her a face-melting weapon that incentives her to walk forward and melt people goes against the hero fantasy she is supposed to portrait.