I've always thought a GTHA bid for the Games has real potential - especially with the IOCs new approach of "if you don't need a venue, don't build one".
LA 2028 will have the canoe whitewater and softball at existing venues in Oklahoma City!
If LA approach of hosting the Games without recourse to taxpayer funds can be achieved... well, that sounds a much better deal than the World Cup...
In light of the IOCs new approach, you can find a reasonable venue in the GTHA (and probably in Ottawa and Montreal too, if needed) for every sport.
Realistically, the main hurdle for a Toronto bid would the main Olympic Stadium. In my mind, the best approach would be to go temporary, even leaving a modest regional athletics stadium as a legacy.
The Parisian approach is very good - they've only built two new venues -
Aquatics Centre (artistic swimming, water polo and diving) and a
climbing wall.
The new things they have built is what the communities actually need - new community centres and pools in one of the poorest regions of France, new affordable housing (well, after its the Olympic Village of course), and substantial new transit lines - Line 14 extensions opened today, actually!