When was that? TTC hasn't done a passenger count on 65 since 2012, but in the same time the 75 Sherbourne has grown from 5,200 passengers to 10,005 passengers - driven by George Brown growth. Meanwhile on the Parliament corridor we've got the Regent Park rebuild (which is surely driving up som of the 505 ridership), and potentially if they extend 65 to Queens Quay, a lot of development there.
Combined Sherbourne/Parliament ridership along that corrridor could well be approaching 20,000 soon, if it's not there already. The Bathurst streetcar is about the same length, and it's only 21,000.