What is the function of the send button on bottom?

There is a send button on the bottom right hand side. Is this to send the response to the question? If so, this seem redundant as most people will tend to hit return to submit their response. Is there some other functionality for this as well?

Yes, the “Send” button is to submit a user’s input. It is intentionally made redundant since we have observed that some users may not hit the “Enter” or “Return” key after typing in their text so they’d just wait there forever if a “Send” button is missing. This is also why almost every messenger app has a “Send” button.

In addition, if a user is filling in a GUI form, the “Send” button will help a user to submit his/her input once a form is complete.