the only reason i ever lose is because im a garbage player anyways. my aim isnt really good. but she is a relatively good counter to tanks because of her melting potential. she is a dva counter because dva cannot fight back besides attacking, once you melt armor its a won duel. plus, you can charge an orb and release it to either hit directly or do a little splash damage to help kill pilot dva.
winston is always gonna be good against sym (unless that sym is an actual god). he can cleave turrets and his shield is good for blocking against your beam, plus he can jump pack any time. but, sym can still fight back when shes at far range. she can win, but it takes some team work and using your range to your advantage.
i would love a little hp increase considering that outside turrets(?) and ulti, she cant protect herself like others. i want tele to open up waaay faster as well, maybe not be so loud lol, but other than that i feel shes pretty good right now, could always be better but whatever, shes fun, ya know? sym 2.0 always has a spot in my heart tho as the hero that got me into this game at all.
edit: i feel sym isnt solely meant for melting tanks like reaper (her kit/weapon isnt designed like reapers or smth for that purpose) but more for squishy targets. of course, she melts pretty much everyone but her dmg is most effective on lower hp heroes than tanky ones.