Firstly congrats on setting boundaries and making the best decision for your mental health. That's a good thing!
I see this burnout in many important professions (e.g. teaching, social work, etc.) and unimportant ones too. I worry what that means about our society overall. If we are all chasing the one or two good marketing or programming positions, it's the same sort of problem.
Americans are exploited in general, and it's not systemic to a single profession or industry. We need more labor rights overall.
Again, congrats on your decision, and best of luck.