Western society puts a lot of emphasis on hard work and tenacity. We tell each other stories of people succeeding under overwhelming odds. We worship survival bias, basically. But for people pushing and shoving through a difficult venture (be it a startup, school, marriage, etc) for a long while, how to decide whether success will actually come and it will be worth the effort? By far, the best advice I have read on the topic is to stay away from such ventures unless it is clear we plan to plow through. But otherwise, the sunk costs fallacy might put us on autopilot.
This idea is a little abstract but involves building tools (could be as simple as a spreadsheet) to help people decide. This can be centred around analysis of opportunity costs and incorporating decision methods from intelligence analysis. It is also possible that different problem areas will command different tools.