Answer

At the moment I’m not immersed in this Talmudic topic, but the medieval authorities (Rishonim) disagree regarding rental: is it an acquisition or merely a legal entitlement? (Apparently this reflects a contradiction between passages in Bava Metzia and Avodah Zarah — “a sale for its days.”) The Taz holds that this is a usufruct acquisition (not ownership of the principal for the sake of its produce, but of the produce alone), and even according to his view this is not merely a legal entitlement but an acquisition. If so, usufruct rights too are not merely a legal entitlement, but a kind of acquisition. It seems to me that, simply speaking, according to Reish Lakish usufruct rights are certainly no less than that.