Burnout for me wasn’t about too many hours. It was more that, especially in the SF tech scene, as an employee you’re expected to drink the Koolaid and not only do your job but be 100% emotionally invested in your company too. The expectation of emotional attachment is, at least for me, what makes working in that kind of environment overwhelming, and recently decided for myself that it isn’t sustainable after 4-5 years in it.