He was poor and largely has been since he arrived, that's a fact.
He has largely been poor yes, true. He wasn't poor Sunday. He had one of the worlds in form players against him and bar one Worldey of a goal(which he was fouled in the build up to) Salah was kept relatively quiet.
Important stats for a defender like clearances, interceptions and tackles show him have had a much better game than poor.
Sure you might not rate him and it might be justified, by at least try to critique his performances objectively.