Food! Everyone has to eat, unless they are super picky, maybe it could be a small starting point. There are also miscellaneous hobbies/things like board game cafes or something the whole family can do together.
When I was that age though I was kind of an ass, but it was mostly because my opinions/thoughts were trodden over by my parents. So everyone recommending listening/talking/showing interest is 100%.
Maybe… maybe they should just cede now, take all the assholes with them… that doesn’t sound so bad.