Having a privileged upbringing can certainly provide you with the opportunities that can lead to an easy life, if you make smart choices when those opportunities arise.
But there’s still plenty of ways Fate can fuck with you. Maybe you’re the type of person who is prone to addiction, and you screw your life up pretty good before you get your addiction (whatever it might be) under control. Maybe you chose a spouse who turned out to be a total asshole and you suffer through years of miserable marriage and custody battles, even though you have done your damndest to be a good partner. Maybe the genetic dice game deals you a shitty hand, and you develop IBS schizophrenia, or fibrodisplasia ossificans progressive. Maybe your horse throws you during competition, and you’re rendered quadriplegic.
TL,DR: privilege can make life easier, but it’s no guarantee.