Separately, I feel like I'm in a rut. I've done more or less the same thing for a couple years now, and I've done all the growing I'm going to in that function. I'm aware of other opportunities within the org, but the lingering burnout/cynicism/fatalism make it hard to get excited about them.
My first reaction is to take a couple months as a breather, and get a fresh start at a new job; leaving baggage behind, hopefully not working myself to burnout again. Aside from burnout, I do really like my company, though – the people are fun, the product is interesting, the pay is good, etc. If I could confidently address the issues above without leaving, I would.
I'm curious if anyone has managed to turn around a situation like this without getting a new job. What did you do? If you switched projects/roles within the same company, was that enough of a reset? Did you end up staying for a while afterwards, or were you gone anyway in short order?
Furthermore, if you feel like you are in a rut, it may be helpful to switch projects or roles within your company. This can give you a fresh start and help you to find new motivation. If you do switch jobs, it is important to make sure that you are not simply running from your problems. Make sure that you take the time to assess your situation and that you are making a decision that is best for you.
In conclusion, recovering from burnout and finding motivation can be difficult, but it is possible to do without switching jobs. If you feel like you need a change, consider switching projects or roles within your company.