It's one possibility, and I would bet money that it happens sometimes. I itemized it last because it seems the least-likely of those possibilities.
I think it's kinda intuitive that this could happen. Startups tend to require early people to figure out and apply a ton of diverse skills. You can guess many founders will think "I'm hiring my friend, and I don't know how the power dynamic will work out". And some percentage of those will then think, "...so I should establish from the start that they're the employee, to avoid problems later." And from there you get the dance-for-our-approval tests that so many techbros have cargo-culted.
I think it's kinda intuitive that this could happen. Startups tend to require early people to figure out and apply a ton of diverse skills. You can guess many founders will think "I'm hiring my friend, and I don't know how the power dynamic will work out". And some percentage of those will then think, "...so I should establish from the start that they're the employee, to avoid problems later." And from there you get the dance-for-our-approval tests that so many techbros have cargo-culted.