When is jungling without smite a good thing?

I would like to know why anyone would not take smite when jungling. Because 90 percent of the time when my jungler doesn't take smite and farms the jungle, we lose because they are still level 2 at 10 minutes into the game. Very rarely do I ever see jungling without smite work, and even then it is bad because smite will out damage anyone else when it comes to dragon and baron. So not only do you have less sustain and wave clear because you didn't take smite, but you also cannot contest epic monsters as effectively because you lack smite. So please tell me when does not taking smite on a jungler ever work and how often or common is it to go jungle without smite?

If it's bad then I'd like to suggest that we make it a rule that a jungle must always take smite. I'm tired of playing games where someone says "i can do it" when trying to jungle without smite. Like yeah, you can back to base constantly and eventually clear some jungle camps, but at the price of being 3-5 levels behind, it's basically throwing the game in my opinion. Not only are you behind by several levels and gold, you also cannot provide ganks, cannot contest epic monsters, probably dying in the jungle by monsters and the enemy jungler invading. At that point, you would do better if you just dual top or dual mid because even if you share exp with a solo laner, at least you won't be level 2 at 10 minutes and be completely useless.