The failure mode is confidence without evidence. Ask for the comparable sales behind the number and you will usually get addresses that do not exist, dates that cannot be checked, or a restatement of a citywide average. Models also carry a training cutoff, so anything they know about the market describes some point in the past without telling you which point.
There is also an American drift problem worth naming. Models trained mostly on United States material tend to produce terminology and mechanics that do not apply here, and a Saskatoon seller reading about transfer taxes, title companies or lender rules that do not exist in Canada is being misled about the process as well as the price.
Where these tools genuinely help is understanding the process, drafting questions to ask an agent, and making sense of documents. For the number itself, use published data as context, the benchmark stood at $444,700 in the latest report, then have someone stand in the house. Joel Dyck's hand-reviewed valuation supplies the comparables, the adjustments and the reasoning you can actually check.