For a long while now, Symmetra has been one of Overwatch's least useful characters in most situations, but that's finally changing with an upcoming rehaul of her kit. The biggest issues with Symmetra have always been just how situational she is: with the rest of Overwatch's cast of heroes, each one has their place in almost any situation and can take full advantage of their arsenal to try to turn the tides in their team's favor.
While the same can technically be said for Symmetra, the strength with which she pulls the tide is rather weak when compared to anyone else that could fulfill her biggest role as a secondary support or defense hero. Symmetra is really only seen as useful on the first point of capture maps on defense, with players almost always switching after the first point is lost. Her turrets cannot be fully set up on defense before the match begins, her health boost to her allies is minuscule and inconsequential, and her ultimate, the Teleporter, is easily nullified and rarely as useful as others. But with her upcoming buff being possibly the largest change to a character's kit in Overwatch yet, all these issues will hopefully go away, and Symmetra will become viable as any other hero, if not moreso.
Starting off the buffs, Symmetra will now be able to place all six of her turrets on defense before the match has started, letting her set up her "car wash" room or whatever she pleases before the enemy team starts pouring in. I'm actually surprised this wasn't just allowed by default; it seems a little silly to me that she can't even set herself up completely before a match like every other hero can, and this is a long overdue change.
Next up, Symmetra's primary fire's reach has been extended, allowing her to more easily connect with enemies and stay connected as she fries them. This is certainly the smallest of the buffs, but any buff for Symmetra is a good buff at this point.
By far the biggest changes are to her secondary ability and her ultimate. While previously her secondary ability allowed her to provide a meager 25hp regenerating shield to all of her allies, this small boost was practically useless seeing as most attacks in Overwatch do well over 25 damage on contact. Maintaining shields was also somewhat stressful, and required Symmetra players to constantly be on top of their teammates. This ability has now been entirely scrapped, and will instead be replaced with something much better: a projectile barrier. Symmetra can now launch a barrier projectile akin to Reinhardt or Winston's, this barrier traveling on a straight path forward once fired.
As for her ultimate, Symmetra is now the first character in Overwatch to be able to choose between multiple ultimates. Alternatively to her Teleporter, which has also been given more health and now regenerates its health after being damaged, Symmetra can choose to set up a shield generator, a new device that is placed similarly to the Teleporter, but deals out large regenerative shields to her allies (75 extra health, to be exact) over a wide radius, greatly increasing her contribution to the team and fulfilling her role as a viable support. These changes are now live on the Public Test Region for you to try out as you please, and will be launching on main servers soon.