This is more like cities driving people out than it is people intentionally deciding to leave. Most of the affordability crisis here comes down to bad local zoning causing an extreme lack of housing.

I’m not sure I agree with you. Toronto is already pretty dense and there’s a crazy amount of construction. I have a hard time believing the problem is zoning.

The core South of bloor is dense but outside of that with exception to a few spots along Yonge and the 401 Toronto is almost entirely single family housing.

Exactly. There's lots of intense density (50+ storey residential buildings) in a small geographic area, but for the other 75% of the land area of Toronto, it has been illegal to build even a 4-plex; zoning allows single family housing only. If you look at neighborhoods in Montreal where there are blocks upon blocks of 4-6 storey low-rise, that type of construction simply doesn't exist in Toronto.

Some good search terms for this topic are "the yellowbelt"[1] and "the missing middle"[2].

[1]: http://www.mapto.ca/maps/2017/3/4/the-yellow-belt

[2]: https://99percentinvisible.org/episode/the-missing-middle/

There are detached homes a 10 minute walk from the CN tower. Toronto is emphatically not a dense city. I recently visited Brooklyn and was amazed.

I've never been to Brooklyn. Would you say it's a good example of an affordable city?