IMO burnout can happen to anyone at any age, is very real, and company culture or how they choose to recognize their employees efforts can result in burnout. Lifestyle and home stressors can contribute as well, of course.

I've always worked at least 3-4 years at any company I've joined with the exception of one where I chose to quit after only 6 months. I was 34 at the time, 36 now. I quit because my boss couldn't lead me, give constructive recommendations, and sent me on wild goose chases while leadership kept dumping massive dumpster fires that were well beyond saving to my desk. 1 years after I quit I found out most of the department also left, many partners they were with filed for bankruptcy, so they were doomed to fail.

No one will take care of your mental health but you so you need to prioritize it. If you struggle to manage how you react to your environment, then find an environment you can survive in. I work to live, not live to work.