I think you're neglecting that most of Toronto is restrictively zoned for SFHs while Edmonton is upzoned across the city for 8-plexes at a minimum.

Toronto has a cumbersome permitting process that runs from months to years, while Edmonton's process is mostly automated and grants permits within weeks.

Regardless, the other relevant factor here is the actual price of housing, which is substantially higher in Toronto... and yet Toronto struggles (by design) to build anything.