Yep, basically any neighbourhood of detached homes built pre-1970s which is when community mailboxes became the new standard.

Not sure that's true, I think it has to more do with whether you live inside a major city.

My last house in Toronto was built in late 2001, and even though it was in the less dense northeast outskirts of the city, I had delivery to the door. At that same time, all suburban neighborhoods a few intersections north of me were getting community mailboxes for quite some time.

I'm in a downtown Ottawa "condo" (row house really) and all the homes around here have door to door delivery. It's pretty common I think.