tbh I don't think it does, with SR in play, which is common, and maybe a level of spikes or toxic spikes then it should be able to be taken out. Either by something faster like Latios w/o QD being used (then again chestorest maybe not). I dunno, I feel like there's a lot of Pokemon that can destroy it and without screens or sun I don't think it's that much of an issue. I mean I only really lost a lot to Volcarona in the early days before I used SR, which I think is a major thing in making it not so bad.
However, resisting the most common forms of priority other than Extremespeed (aka Bullet Punch and Vacuum Wave/Mach Punch), only really Sucker Punch stands a chance and if you don't have that in your team it's kinda a struggle, but I don't think that those things necessarily make it such an issue, especially against something like Unaware Quagsire.