Are 'consent' and 'affirmative consent' identical? If they are, the entire theatre around 'affirmative consent' is a ridiculous, pointless, stupendous waste of time.
If 'consent' and 'affirmative consent' are different, that means that when two people have sex, there might be consent but not affirmative consent. What does this mean? Is it rape if there's no affirmative consent? Isn't consent the only thing that is sufficient and necessary for sexual relations? If not, why not?
Affirmative consent precludes cases where someone consents to sex, but is in a state that the person having sex with them cannot reliably tell that they consent. The oft-used example is an intoxicated person who does not show much responsiveness.
Put another way: if the person having sex with you is unable to discern whether or not you consent to sex then they should assume that you don't consent. It's affirmative consent in the sense that a simple failure to resist or decline sex should not qualify as sex.
Of course, most people don't need to be told to do that because they already use the affirmative consent standard, but a minority of people apparently do. If it weren't for that minority, advocating for affirmative consent would indeed be a waste of time.