Logically, the more dispersed people are the less concentrated they are in any one area. Obviously. That said, Toronto is extremely walkable. Maybe not as much as certain European cities (I honestly wouldn't know), but everyone walks everywhere in Toronto. My wife and I had a dinner reservation with friends one night and we chose to Uber instead of walk because my wife wanted to dress up and wear high-heels. Big mistake. The walk would have been 25m, the Uber trip took over an hour. Toronto even has the largest indoor walking path network anywhere in North America, it's something that Toronto prides itself on and was motivated by our cold winters. The point being, you don't need to walk on sidewalks on roads. You certainly don't have to drive (and most people don't). And there are paths all over the place that short-cut through buildings, parks and court-yards etc and avoid busy roads.

And still, you can't find yourself anywhere in downtown Toronto where you're not trying to dodge people or get one second to yourself without having people constantly around you anywhere that you look. Though my definition of "crowded" likely differs from people who don't mind being around people as much I as do. Our friends told us that we would despise New York given how bothered we were by the amount of people in Toronto.

So I'm skeptical that there is some high-population-density major urban centre where crowds would not exist on a level that makes me feel uncomfortable. At the same time, I'm happy to say that cities, in general, just aren't for me. Fine to visit from time to time when there's some special occasion (comic-con, concert, trip to Vegas or what-have-you). But not a place that I would want to live no matter how "walkable" they are. For my preferred, secluded & remote lifestyle, a vehicle is a necessity.