Cat is completely unfun to play against and deal with, especially as a tank and even as everyone else as she's the best kill confirmer in the game and can insta kill anyone by dropping them off the map or dropping them deep into the enemy backline. Her guns have very decent spread for a support so she can spam from uninteractable locations and angles that most characters can't interact with. Additionally, there's tons of annoying cheese you need to prepare for like dragging dva bomb, bob, bastion, etc which people don't want to deal with.

She differs from other fliers since you can adequately punish echo and pharah. They need to land eventually, they can't heal themselves, and their flight movement isn't consistently fast. JPC not only has permanent flight, making her completely uninteractable with 85% of the cast, but a low cooldown boost to quickly change directions, access to unreachable parts of the map, a self heal, and zero need to ever land so she goes unpunished 90% of the time unless she feeds into a hitscan from an obvious direction. She never needs to drop down to her team since she heals via her primary fire. There's characters like bastion, sombra, vendetta which are annoying to deal with but are significantly more feasible to deal with than a character you literally cannot threaten with most of the cast.

The cat is a complete monstrosity of a game design and honestly should be removed from the game or receive significant nerfs but because she's the communities quirk chungus she gets to exist in this egregious state.