I'd carefully weigh any advice received with the experience of the source. Not to say that anyone that has not been in a similar situation had no value. But rather people who have had similar experience will be of more value.

That being said these are the considerations that were in my mind when I was in a similar position.

1. Just like an investor or even more so, how much do I believe in the founder. 2. How confident are you in your abilities. Are you able to cope with stress/uncertainty and preserver in the face of daunting tasks. 3. How much do you believe that there is a business somewhere in there?

If you are enthusiastic about all 3 the risk is worth it. Feat and doubt are poor reasons to not do something. Fear is a good sign to pause and evaluate the situation. There is only one way to find out if you have what it takes. Also if you think taking a low income (or no income) is a big issue now. It only gets harder as you get older. Wife, kids, mortgage and general lifestyle inflation.