Given how quickly the proposed TOMQ HFR plan is progressing, an HFR line to Buffalo seems to be quite well entrenched in the realm fantasy.
I agree with you regarding Toronto-Detroit, but I was talking about Toronto-Buffalo. It is true that Toronto-NYC does struggle to be competitive with flying because Lake Ontario is in the way. As we have said before, the gravity model is interesting, but it hides synergies between cities. That is why despite Toronto-Montreal having double the "Ridership Units" of Toronto-Ottawa, actual ridership is higher on Toronto-Ottawa (Toronto and Ottawa are in the same province, they have the same primary language, Toronto is Ottawa's provincial capital and Ottawa is Toronto's National capital). Both NYC and and Buffalo loose a lot of "points" in synergy for being in different countries. Having said that, NYC is at least the USA's economic centre and a major entertainment centre. Buffalo doesn't really; have any significance. There might be some travel for sporting events, but the train would struggle to compete with the car for that (people tend not to go to games alone, so the cost of train fair is proportional to the number of people traveling, and unless there is a late train that aligns with the end of the game, you have to delay the return to the next day). Then there is the whole issue of needing a passport (or enhanced driver's license), which not everyone has (especially south of the boarder). Am I missing something about why Buffalo would be such a great business or vacation destination for Torontonians?
Correct me if I am wrong, but I did a quick check and couldn't find any direct flights between any of Toronto's airports and Buffalo, so I don't know how that helps your argument.
https://algnewsletter.com/land-transportation/air-vs-rail-can-rivals-become-partners/
While I do tend to agree with you regarding Detroit vs. Chicago, I don't see why investing HFR to Buffalo (bypassing Niagara Falls) should be a priority for the Canadian government.