So this is the first time I've heard of the 15 minute city concept, especially as a bad thing. I live on a farm but if I wanted to move to the city... 15 minutes to everything sounds great. Isn't that sort of convenience kind of the whole point of a city?
My ex lives in Moose Jaw and that's a pretty good description of it, it's 15 minutes drive from edge to edge and it's honestly a really nice little city. No traffic jams and you can also walk or bike most places you want to go, as long as the weather permits.