How to create a legacy and stick with it

You have my admiration, I cannot even stick through one generation. Legacies are just too boring for me. I have many families in my main rotation, and I rotate at pleasure and age them up when I want. My families pretty much all know each other here and there, belong in clubs etc. and I have aged very few up in the last 5 years. When I did try to do legacies in sims 4 though I would go in and mix families, give them children about every time my sim would have a child ( I don’t use mods ). I have thought about trying some kind of castaway game with chance cards drawn at random. In fact, if Maxis gives us another pack like Strangerville I hope that it is some kind of castaway pack where a boat load of people get stranded with chance cards. I loved ‘lost in blue’ and would sure like to see some of those elements in a game pack. I hope it’s a bit more challenging than Strangerville though, but the challenge can either be toggled on or off depending on the save ( I’m not sure I would want to mix it with my main rotation like I did Strangerville.