Some of that is just Tolkien's dictum:
Now it is a strange thing, but things that are good to have and days that are good to spend are soon told about, and not much to listen to; while things that are uncomfortable, palpitating, and even gruesome, may make a good tale, and take a deal of telling anyway.
But happy families have another difficulty: You can always throw in problems from the outside. The problem is that they have to be big enough problems to plausibly take everyone's abilities to take them out again. And probably not in a brute force sort of way. Getting everyone to push, or to cast a fire spell, or what have you until the problem yields just underscores that the writer had to make the problem that bad to get that to work. Even giving them a problem that too neatly enfolds their exact abilities can look engineered. And readers can be very unfair to characters who aren't instrumental in the victory, even when they reasonably would not have the skills required. (Small children excepted. Then again, you have to engineer it to have the reaction be other than "Why are those horrible parents dragging their children into danger?")
Plus, of course, orchestrating the characters so that their personalities aren't carbon copies of each others. Redundant personalities are even worse than redundant powers.
The Incredibles pulled it off. Though partly through some unhappy family life, by the time the action really rolled around, that was not the problem. They coordinated the powers well without making it obvious that it was what they were doing. Not many others like that.
Putting it in the backstory can work too. Especially since it gives whatever character is left a powerful motivation, to rescue or revenge. Just picked up Blue Yonder, where the happy superhero family of a father, mother, daughter, and son appears in flashbacks. We have his sister appearing in the opening prologue, but she's caught trying to protect him, and so we end the prologue with Jared alone and desperate to rescue his family.
You could get some interesting conflicts about someone trying to rescue or avenge a family he loathed, but it's not exactly required. A bit of cliche, even, but nothing gets cliched without good reason.