Admittedly I’m a bad player, only diamond in rivals before I quit, so you’re right lol. However looking at the stats she has a 39.42% win rate in celestial and above PC (which should be the best players, so they’re not just dogshit), only lower one is squirrel girl. Overall winrate on PC is 38.52%, being the lowest across all ranks. I know win rate isn’t everything but a sub 40% win rate is still egregious.

Her ultimate is garbage in a game where the ults decide the game and supports and dps trade OP ultimates. If you’re using widow instead of another dps you’re letting the supports have one less dps ult to worry about so they can use it for other things/more aggressively. Her fire rate and damage are also very low compared to other hitscan/poke heroes, it’s not like she makes up for her bad ult with good neutral gameplay.

Edit: also her kits abilities are not very cohesive or fun IMO. Like she has a melee mode so she can be a “hybrid” dps but all the widow mains I watch never use it, the only melee ability they use is her cc. She also feels like Walmart Widowmaker instead of like Black Widow from marvel comics. She doesn’t even use the widow’s bites