How much time do dogs spend uncomfortably needing to poop? I expect many humans would agree with this statement: “If ...

How much time do dogs spend uncomfortably needing to poop? I expect many humans would agree with this statement: “If I need to wait more than a few minutes for a place where I can poop, it’s often uncomfortable and sometimes painful.” It seems reasonable that other mammals would have a similar experience. Given that many/most dogs spend at least part of the day alone, with the sanctioned poop spot behind a door they cannot open without help from a presently-absent human, are these dogs having a good time? (Corollary, why don’t we give dogs litter boxes?)