I worked for failed startup, and now I work for successful startup. How do I know the one I work for now is successful? Founders are transparent about burn rat

I worked for failed startup, and now I work for successful startup. How do I know the one I work for now is successful? Founders are transparent about burn rate and available funds and also they do not hesitate to share information about revenue. This does not sound like much but from my experience is already a good sign. Maybe some users here will find it difficult to believe but previous startup I worked for (the one that failed) was not transparent at all. We would hear stories of potential big.co customer that will bring millions and then... we would hear about another potential big.co customer that would bring millions... And every month or two we would hear the same story. And then one day we was informed that the company can no longer keep us so we are released with immediate effect. Revenue is (usually) a sign that people want the product you build. And if people want it hard enough to put their money into it then you know you solve a real problem and that there is actually market for it.