Not AI but Ive seen a lot of social startup apps in my time all trying to be the next facebook with a twist. They all end up in the same place. If you have any idea along the lines of "Do/share X with your friends" it has probably been tried a million times before so just don't. Another one is dating apps. Everyone thinks they all suck and everyone thinks they have the new twist that will make it not suck. End result is so many shitty 'ghost town' dating apps that end up looking and functioning like the other 99%. Once in a while a Snapchat or Tindr will break out with a genuinely fresh idea but for every one of those there are a million carcasses of failed startup ideas

I worked in a consultancy/agency 15 years ago for less than a year (it wasn't for me) and in that short span I witnessed 3 "facebook with a twist" projects. Code was delivered, but they naturally failed to gain any critical mass whatsoever. Also having startups getting a consultancy to do their code was already quite strange.

I specifically remember one of them being "facebook for dogs" and another being for restaurant professionals.