OPES will increase the integrity of content delivery over what is available today.
It is of only academic interest to contrast a pure end-to-end world against a world with OPES.
As another purely academic exercise, contrast a pure voice switching model against the Internet. The Internet offers many opportunities for traffic monitoring, substitution, and malicious intervention that the phone system did and does not. Whether or not the benefits outweighed the risks was not evident a priori; in the case of OPES, you cannot make such an evaluation simply by pointing out risks that are already there without OPES and claiming that OPES somehow makes them worse.