If a pair of animals (humans included) can raise >2.1 offspring that have >2.1 offspring themselves, that's potentially a functioning species. Now, humans tend not to like this minimum requirement because we frown on dying as grandparents at age 30, but it works fine from a species point of view. That's why the answer to "But how does [animal] deal with [common issue] in the wild" is usually "it dies"