I'm in trouble then, my 13 mini has 88%! I just use it pretty heavily so I'm sure I've charged it up too many times, the cycle count has to be really high already.
A particular problem with the iPhone 5 I've found. I own several older iPhones and the 5 is the only model that I've ever had that has done this. And a work issued 2015 MBP had its battery swell up too. That (battery) was replaced and the tech told my boss he was very surprised it didn't damage internal components.
I also have a crap Android tablet that was given to me many years back that the batter swelled on. Managed to push its screen entirely off the casing. But that's not an Apple device.
I think part of the issue with swelling is leaving a device on charger for long periods of time. In the case of my work laptop I've taken to disconnecting the charger every day when I'm done with work and leaving it off charger on weekends. It sits in clamshell mode all of the time and is set to operate under full power with no sleep when on battery. By doing that I know the battery is charging and fully discharging. Been over a year since the battery was replaced and I don't see any swelling so I guess this plan is working.