I don't think my iPhone was ever damaged by an update - I always migrated to a newer one before the newer OSes caused strain. I was one of those who held off on

I don't think my iPhone was ever damaged by an update - I always migrated to a newer one before the newer OSes caused strain. I was one of those who held off on the initial releases of iOS 7 .. But my god Yosemite in 2015 (again waited for it to "stabilise") on my 2014 MBP was an unholy shitshow.