Why don’t they sleep in their tents?

This thought randomly occurred to me, why is it that when you long rest, your companions who are in your party don’t sleep in their tents?

The tents look like they were very elaborate to set up and our companions stand in front of them when they are hanging out during the day, but not actually sleeping in them at night.

Why would they go through all that trouble to set up their tents and not sleep in them?

I know I’m overthinking this and it’s just a game, but I have to wonder why they don’t use their tents lol.