That block-to-block variance is the whole story here. A property two doors from a renovated strip of restaurants and shops behaves differently from one further from that activity, so a citywide or even neighbourhood-wide average tells you very little about a specific address.
Suite legality decides the financing side regardless of location, since only a permitted secondary suite can be counted as income by a lender under standard underwriting, and the Residential Tenancies Act, 2006 governs whatever lease is already in place.
The right answer for a specific Riversdale property depends on its exact block, its permits and its actual rent roll, not the neighbourhood's reputation. Get your hand-reviewed valuation from Joel Dyck.