I agree that that has the same meaning, but I think it may have a different grammatical structure, with an entire subordinate clause that was missing from the original. Since the voice of a verb is a grammatical rather than semantic question, this seems relevant; "in addition to the points people have already made" is also (probably) semantically equivalent but unquestionably uses the active voice.
I agree that that has the same meaning, but I think it may have a different grammatical structure, with an entire subordinate clause that was missing from the original. Since the voice of a verb is a grammatical rather than semantic question, this seems relevant; "in addition to the points people have already made" is also (probably) semantically equivalent but unquestionably uses the active voice.