[codexon]

An entrepreneur is a more difficult job that requires you to be good at more than just programming. A capable entrepreneur imo, would not be churning out random super niche websites like the ones you just listed, hoping that one of them sticks.

Market research takes time and effort, just like programming does. If you do not already have an idea you know will make you money, you will need to put in the time and effort to find one instead of using that time making random websites. Some people do get lucky and find a niche without much effort, but that is likely not the case for most.