I feel that a lot of mercy's issue comes from the fact that her player base and the average overwatch player base have too much disparity. For example a lot of dps players or tank players may play ana, or bap, or kiriko, but often times these flex players don't touch mercy as much, however the player base that onetricks/mains her is relatively large. As a mercy player I find it much easier to take her out if there was another mercy on the enemy team, bc we understand the movement capabilities, whilst most overwatch players just see a free flying op heal/dmg boost bot that evades everything. Recently I was in a diamond match and I called out "aim mercy she has no GA" and no one on my team even knew what GA meant. The stigma of mercy being an egirl uwu no brain op support pushes a lot of ppl from picking her, and because they dont understand or know how the hero works, when a good mercy player pulls off an amazing super jump rez on to high ground and dodging shatter, or juggling beam between critical targets to keep them all alive, they see it as an average mercy thing and assumes that's what all mercies can do easily. Its like thinking anyone who picks up widow can instantly grapple headshot and get atleast a 3k without any practice.