In that respect I think Stardew Valley has included much more complex and compelling mechanics, as it seems designed foremost to appeal to adults. I thant is where it really shines over Animal Crossing.
Stardew Valley is also a different kind of game. It's a Farming Simulator, while Animal Crossing is usually called a Life Simulator. They both do kinda similar thing, but with very different focus.
In AC you collect stuff and arange/design stuff. And you also build stuff, for collecting and arranging stuff.
In SV you Farm, literally, and you plan how you farm the most efficiently way. You even have a energy-system and limited time, and have permanent pressure to do things now and not later. You can do build things, but AFAIK only for farming.
Both also have other mechanisms, often the same as in the respectively other game, but in some significant lesser complexity.
>have permanent pressure to do things now and not later.
I have not played SV, but I have been a farmer. I find it fascinating that the game makers managed to get that mechanic into the game, because that is 100% farming. "When it's time to make hay, make hay" is a saying you hear almost every day as a full time farmer. If you don't get it done today, it may rain tomorrow and then everything will be ruined, is the sentiment there.
I don't know that there's anything else to this, or that it's really that interesting. But I find it interesting that game creators, who I assume were never farmers, would work that into a game that seems to focus on farming. The stereotype of a farmer, from what I can tell post-farm life, is to be laid back and sort of let life happen around them.
