Does it work?
The thing you’re working on, does it work?
Why? Why not?
Whatever the outcome. Look at it from an evolutionary perspective: what works in the current conditions survives.
So if a project is failing, it is failing to adapt to conditions. It could be failing because there is little runway (money, energy) for adaptation, it could be failing because it is adapting in a wrong way (perspective, direction taken), it could be failing because it is adapting too slow (conditions changing too fast).
If it’s succeeding, it’s adapting well.
Sustainability, vision, environment. Distinguishing those is important for diagnosing and finding a possible cure for failure or a recipe for success. But even before that there is a more important step. Asking and truthfully answering a simple question: does it work?
Does the project you’re working on work? Is it changing the world for the better? Yes or no?