Being straight forward and honest is relatively easy. Doing so in a agreeable way to your audience is a lot harder, and usually a highly sought after skill.
Surely the most significant side effect of any F2F interview is to evaluate social skills. An answer that the interviewer fully expects to be a lie just isn't required.
Anyway... "Why do you want to employ me over other candidates ? "
For people who lack social skills the best way to pass those test is to lie, wich is pretty easy.
The god awful truth is that most people just want money.
Why so many companies can't just offer this and get some dependable, competent employees and be happy with that, I'm not sure, but I know it has something to do with the mentalities of people who become founders or high-up managers.
I didn't mean to imply anything about lying or misleading. Similarly, I don't think it is manipulation to consider your audience and what they are trying to ask.
The best coworkers I've had were honest and straightforward, but could understand and emphasize with their audience too. I think everyone who takes this question literally at face value is missing the second half of that.
I think most people want a nearly endless list of things, of which money is just one of the most important.
For example, most people won't be happy with if you give them money but treat them like shit and over work them with frustrating tasks.