The purpose of debate isn’t necessarily to convince the person your debating against. It also helps sway others who might be party to the discussion. Just because I have a line in the sand re: turning over control of my computer doesn’t mean I can’t debate that point and offer my own reasons for taking that position, while someone contrary to that can explain theirs. Neither participant in the debate needs to budge in their position, but by both offering their reasoning it may be useful in persuading others to one of their sides.