Is it because of the idea, or is it because of other factors? Or the idea combined with other factors? Addressable Market? Marketing savvy? Sales leads? Product execution? Luck/Viral Posts/First Mover Status?
I like that this common criticism was brought up in the article:
> "Doesn't this exist? So many big platforms do it. Very competitive."
This is a validator in itself. A small business can see an existing, competitive market, and that's usually an indicator that there are a lot of potential customers. If you look at products like FastMail or Hey they aren't so concerned that 95%+ of people are fine with the big free email providers, because literally everyone uses email at some point.
I think my overall point is this: The "idea" part of a startup is perhaps one of the less important aspects of it, in my opinion. Maybe it's even the least important part of the equation.