Perhaps we define stress differently. How can burnout happen if you love every little second of your day and everything you do fills you with joy and energy?
Why not? Let's bet a few people do. There are certainly people who live their life in a permanent joyous state, no matter what. Rare, perhaps but I wouldn't dismiss their experience as a condition.
You can work in relatively low stress job, but not love it.
It can be boring, mundane, unfulfilling, uninteresting, repetitive, etc... That doesn't generally produce a traditional "stress" but does wear on you emotionally.
Then you've never been an athlete at a high level. I don't mean that negatively, but I can assure you that even people who love every second of what they do, like many professional and even college athletes, can suffer burnout. Exhaustion and stress can cause burnout in anybody.
Not really. I've had jobs that I hated, but that weren't stressful at all, because it was just a thing I had to do to get money, not something that mattered.
In fact jobs I loved and cared about have often brought much more stress exactly because I cared about the outcome, and when I failed to live up to my expectations at that job it felt like a personal failing and I was letting everyone down.
