from my experience mercy and symetra are kinda dull to play, I don't feel they require skill to play. I really hate playing them.
the game as a whole is more about positioning and teamwork than aiming
you have to be alive to help your team and such, symmetra isnt really that useful though and i think she should be in defence instead
tfw mercy potg after saving your rez for like 4 people at once instead of wasting it on one person
same as medic in tf2 really, he didnt have any shooting weapons either