There’s a saying known as “beauty is skin deep”, and I think that applies here. There are likely movies that have beautiful animation but horrible writing, characters, etc. in many people’s eyes. Animal Crossing New Horizons could be the same to many people.
I get what you are saying and can somewhat see truth in it, but at the same time a game like Animal Crossing will always have a "shallow" part to it I feel. There is only so much you can do when working with AI and you can add in a million different items, in the end that only adds a "plastic" depth. Given what you can do to extend or deepen that shallow feel, I feel they did a lot, by the massive amount of charm and customization. The parts where they can add depth, I feel they did it quite well. But I do see where you are coming from. It must be tough as nails though to make a game like Animal Crossing feel like a deep and immersive experience.