I don't know what USians or Canadians call bacon. I'm in England. You can get low-fat trimmed bacon, but even that has some fats. It's also salty. And it's often served with some sugars. (ketchup).
This fat / salt / sugar combination is supposedly a great combination to make foods palatable. Here's a review of a book by a former FDA administrator:
It most certainly is. Vegetarian bacon, while good, does not taste like bacon. And bacon with all the fat removed does not taste like bacon. It may be good, but it's not bacon.
Vegetarian "bacon" salt is still delicious, but not fat (and has a rabid fan base.)
Fat is delicious, but bacon is not delicious because it has a high fat content.