I've been talking recently about something similar. I don't think the issue - from a storytelling perspective - is difficulty as much as it is stakes and nothing made this clearer to me than when I developed a story with a single mom raising four children. I knew the mom was going to die, but I still wanting to witness the story of her developing a relationship with her children first - helping them with their homework, celebrating every good decision they made - and it didn't take long before she was at 100% with all of them. But when she died, they all had a sad moodlet for 2 days - often shorter if they did something like jog or write in their journals! - and afterwards, *totally forgot about their own mother.* Death was rendered utterly inconsequental. It was impossible not to notice, too, that there was no option to tell someone you loved them. And in real life, seeing Angie erased from her children's minds kind of broke me.
So for everyone talking about how you want to play in a utopia, a world in which people forget you ever existed two days after you died is not a utopia. A world where you can make anyone you want love you by being in a good mood and flirting with them is not a utopia. That is an awful world where life has so little value to people that existence is merely the consequence of a series of whims based on spontaneous emotions, where love is dictated instead of earned.
If Sims 4 wants to create a utopia, it at least needs to create the illusion that the people in the world matter. That their existence has a lasting effect on others around them and that they have the ability to choose to love, remember, and do good or evil.
What Sims 4 needs is stakes, if just to make things a little more interesting. Unequal romance system so that we have to explore romantic relationships. Evolved grieving systems so that we understand death has a lingering impact on people (and should! Because people should matter!). An evolved sense of the evil trait where characters can actually hurt us so that we are encouraged to spend more time actually getting to know the sims around us and deducing their trustworthiness. Sure, there may never be a game to accurately represent Gentrification or homophobia or self-hate or etc., and so there has to be a natural limit to how far the game will go. But a game that *promotes* the idea that a utopian world is one where things always go your way with little effort and you can have whatever you want whenever you want and that people will always be whatever you want them to be is not a game that even sort-of encompasses the beauty of the human experience. That is not playing with dolls. It's playing with slaves.