The reality is that you can burnout in any of these ways whether or not you're a corporate monkey or a start-up monkey. Substitute vending machines and water coolers for fancy free-for-all-cafes and foosball tables, and many start-ups have similar WORK demands of their employees. In other words, no matter how fun the culture, it can't forever mask the fact that you're working toward someone else's vision and mission.
I once thought this would be very different in a company of 50 vs 50,000. But even in start-ups, we suffer from an over-emphasis on specialized activities (for efficiency and scale). This creates jobs that lack ownership of the big picture, and therefore may create short term excitement (if the work or team is interesting), but does not equate to long term passion and fulfillment.
As a founder with an idea, part of the reason that I don't want to join an existing effort is because I want to build an organization that challenges this model. Is there a way to better distribute ownership of the vision to everyone in the company so that instead of having a bunch of employees working toward your vision, you have a bunch of entrepreneurs collaborating to define that vision? That in my mind is a major part of avoiding burnout.
The secondary piece is helping people realize that work/life balance is always necessary. As a founder, I spent one month subscribing to the Valley norm that I should just work constantly. Mentally I was fine, but physically I pinched a nerve (or something) and all kinds of horror happened. Yet this cultural attitude of fast fast fast is so prevalent, I think we should also do more to encourage people to adopt some "slow" principles.