We have 8 dogs and live in a very small community with no limits. So no problem, there.
However, we used to be in a city that had a 2-dog limit. At the time we had three dogs, but we had one registered through our in-laws so all three could be licensed. In most cases, it seems there is no enforcement unless a neighbor complains or someone sees an obviously neglectful situation. Which, of course, means that even with limits, there are animals in abusive or neglectful situations that fall through the cracks. In fact, I suspect that most abuse/neglect is hidden indoors and never detected. So I'm not sure what the setting of a limit actually does for the animals. People who will be out of their element are not going to be stopped by the limit, but some people who could handle more may be prevented from doing so by following the limit.