The answer is literally always “It will allow me to pay my bills. This won’t be a giddy, young-love crush of a hobby for me. Hire me and I’ll just do good work, not cheerlead.”

The question is a synecdoche for “How awesome do you think we are, and so how much will we be able to coast on our respect for you as a result?”

Not true. I can think of a bevy of reasons that I'd be excited for a role that have nothing to do with being a cheerleader. For example, working in the banking industry for many years, I was tied down with a very rigid, sometimes antiquated tech stack. I started applying to smaller companies because I was excited about the prospect of having more autonomy and being exposed to a more modern tech stack.

I'd love to hear this answer. So much better to work with honest people, who's not afraid to call out BS.

yep! you nailed it. "because I have bills to pay" is the true reason. But they want some flowery "your mission really resonates with me" BS answer.

The truth is most people's aim will be get more money, isn't it? but employer usually wants employer say something "big", they don't like the answer: for getting more money.