NYC has so much more historic building stock that heritage designations are reserved for basically only the true landmarks, arguably as it really should be.
Toronto's heritage regime comparatively has much less to "preserve" as the city is so much newer, so basically everything over 50 years old gets a heritage designation, and that designation only protects the facade of the structure.
Honestly I agree that a more restrained heritage approach only protecting the most significant buildings but with quite strong protections instead (i.e. no facadism) would probably be a better approach overall.
Remember that Toronto was smaller than Buffalo until the late 1940's..
https://urbantoronto.ca/news/2012/08...y-toronto-1930