Not sure I would take such a binary, simplistic view. Of course every city is different due to politics, nation, climate, population, geography, etc. But we can learn from others still. Saying "we shouldn't have highways through the middle of our city cause it hurt places like detroit" is the same as saying "we should do grade separated bike and walking paths cause it helped vancouver." We can learn from others, we don't need to reinvent the wheel.
I'm not advocating we copy vancouver's overall transit, condo, etc strategies. But we can look at their main streets, bike infrastructure, and residential interaction with street fronts to find improvements to make in our city.
The thing with some of these "truths" is that most of them have been tested and the results have been showed in several different places, with different geographies, cultures, climates, much to similar results.
Highways cutting through (or boxing) the core areas, especially older, mature neighborhoods usually yields sterile, non-walkable, non-livable downtowns. Happened in dozens of North American cities, happened in South America (Rio, São Paulo, Caracas...), Asia, Oceania and, even though to a lower degree, Europe. Cities that avoided and/or got rid of them generally see a much more integrated core, that could be redeveloped into residential, commercial, instead of just corporate. Examples are many: Seoul, Melbourne, Tokyo, NYC, São Paulo, Vancouver, Santiago, Buenos Aires, San Francisco, Boston (recently, with the underground highway).
Having more (well designed and implemented) bike lanes and walking paths, generally improves the urban experience and have a positive impact on business and residents at the same time, especially in denser, mixed use neighborhoods. Again, examples are not lacking: Amsterdam, Paris, London, NYC, San Diego, Rio de Janeiro, Mexico City, Shanghai, Kyoto, Jakarta, Taipei (and that is not to repeat myself a lot with the same cities, but São Paulo, Santiago, Tokyo...).
More efficient and available transit has been proven to improve general quality of life, creates incentives to densification and development in different areas and connects areas that would, otherwise, be segregated (hence some NIMBYs resistance to transit, especially rail, coming to their neighborhoods. São Paulo, as big and cosmopolitan as it is, suffered with this for decades in some areas that were crucial to have subways going through and to).
What we need to do is look at all of these experiences and find out how to better apply these concepts to our city, taking advantage of our particular characteristics (the River Valley, the flat land profile, the well defined seasons and even the generally dryer, colder climate), like
@archited said. And we can use a catalyst to help us justify some of these changes that we'd like to see made and which wouldn't even be discussed in normal times, be it a global pandemic that shifted a lot of jobs to permanent home offices or the FIFA World Cup that will require the city to improve its branding, attract hotels and bring in tourists to our Downtown and fill our transit with riders and, if we take advantage of that exposure, could help the city attract people, companies, etc...
