It's a 5-star great game if there's is only one player in your household.
If you have brothers, sisters, parents, kids want to play the game as well (no necessarily at the same time), is going to be a big test to your family members' relationship.
AC only allow one island per switch console.
Creator of the island will be the main player. The rest of the family members will have to following around the decision made by the main player. The resources quantities will not not change no matter you are playing alone or having 8 players on the island. So, take it outside, go fight it out...
Nintendo is trying very hard to get everyone in the household to have their own switch, so they can enjoy the full experience of the game... Nah, not going to happen... Greedy...