I think you are right if you assume that people generally keep their checking account balance at exactly what they need. If that's the case, then I agree, there isn't really a point to what we offer.
However, doing that is really hard, and requires you to micromanage your checking account. I personally (before using FC) had $10-20k in my checking account, because 1) I really want to make sure I don't miss a rent payment because I mess and 2) I don't want to micromanage. So, at least in my situation, some of the money is moving in and out and can't really be invested, but a decent chunk (probably >10k) just sits there. I imagine this is true for many people.
While I do wish the best of luck with your product, I feel like there's a difference in checking account needs for people with 10-20k of cash sitting around and people who live paycheck to paycheck. I think calling it anything close to a checkings account leads to "this isn't a checkings account and you're going to hurt people who think it is."
However, doing that is really hard, and requires you to micromanage your checking account. I personally (before using FC) had $10-20k in my checking account, because 1) I really want to make sure I don't miss a rent payment because I mess and 2) I don't want to micromanage. So, at least in my situation, some of the money is moving in and out and can't really be invested, but a decent chunk (probably >10k) just sits there. I imagine this is true for many people.