Ask HN: When should founders stick to their vision and when should they pivot?

I’ve worked for two founders now that seemed to have been wandering in the dark. With money, but no clear vision and looking for the industry to tell them what they should build next. The first one had their original product wiped out by lockdowns, the other sees the writing on the wall, but for the time being is still using it as a cash-cow. On the one hand, I criticize them for not having a bold vision and then taking a big bet to make it a reality. On the other, I respect the idea of taking a data-driven approach by making small bets and seeing how they play out. Neither has succeeded or failed [yet], just limped along. I question if the later is inevitable. A long drawn out death by mediocrity.