Is that how it works, or do lots of people build lots of things, and when a tiny handful of them go big the creators are retroactivley deemed prescient?

I think that there's no question you have to do some things right to succeed, but many people do things right and fail, because ultimately, a lot of it is just pure luck.

A lot of it is that the people build things they know will work (rather than things they think will work) tend to succeed more often. (At least in my own admittedly anecdotal experience) The hard work of research, initial sales and market validation is later retroactively glossed over as "vision" by onlookers.

Everyone is convinced that their startup is the next big thing. Some of them end up being right. Part of that was prescience, part of it was the "luck" to be obsessed with the right idea.

It's more about recognising when you're on to something, and when you're flogging a dead horse.

And being able to double-down quickly in the first instance, and trash-can it in the second.

And getting what you built into the hands of the people that need it is nontrivial and I'd argue it's the hardest part.

True. The reason why this went well for the developer is that he did direct sales to find early advocates, and didn't rely on an app store magic wand. Of course, that is possible with a $199 app, not so much with a $1.99 one.