There's hardly any AAA titles that use Unity, the most well known ones are games like Hearthstone, Cuphead, Beat Saber. These are great games but they're not exactly GTA 6 or Call if Duty.
But on mobile it is king, and mobile is starting to get games that can rival AAA studios in presentation. Genshin Impact and the rest of Hoyoverse's games are all in Unity, and while not confirmed I wouldn't be surprised if Project Mugen is also running Unity (given that most of NetEase's portfolio relies on it). So it has the capability to handle AAA games, even if no one in the west is utilizing it.