To be fair Symmetra has never been a troll pick. She has always been incredibly strong in the right hands. People just formed their opinion on her, and as such labelled her as a troll pick/ situational (much like Hanzo or Widow pre-sniper meta).
Symmetra’s current kit is perfectly fine. She can take up a DPS slot and can help loads. If the enemy team has tons of squishies or have a habit of going out on their own / out of position is a really good thing for Sym as her turrets can be super punishing onto a Lucio that’s away from his team or trying to contest point.
Her ultimate can block off a choke from damage while the Rein is recharging his shield. Her level 3 beam can melt multiple team mates in record time. Her teleporter can help to move your team to high ground none/ not all of you could reach before as well as provide from interesting flanks (especially with the help of a Mei wall). Her alternate fire can provide lots of splash damage into a group as well as assist in shield burning (her primary fire can also help with this, especially with the whole no using ammo to hit shields thing).
As much as I LOVED old Sym, I feel like this is a better place for her. No longer is she screamed at to change to healer because she’s “taking up the second support slot and we need more heals”.
She’s only a “troll pick” if the person who’s picked Sym doesn’t know how to play her.
Which goes for any character.