I imagine the rise of this sort of mimicry leads investors who previously would consider investing in an idea and seemingly great founders to more strongly favor traction. I wonder if the YC partners keep track of the change in the percentage of startups accepted with an idea alone or complete a prototype just before an interview.
I'm also curious about the percentage of successful (or surviving) YC startups that were accepted with no traction versus those accepted with a product that had a quickly growing number of users. This value may be misleading, though, because the sample size isn't enormous, and there are so many other variables that affect the survival of a startup.