That’s the biggest issue I can think of. You can only water so many plants, chop so many trees, and pick so many rocks in the mine before you run out of stamina. I’ve had plenty of times where I would go to bed at 2 PM because there was nothing else for me to do. Having eight characters means 8x the stamina, so you can do 8x more work per day. But even for the things that do not require stamina, there are only so many items for forage, so many villagers to talk to, etc.