Can I spend the night in T3 Terminal of Capital Airport because I have to transfer in Beijing?

Once, due to the heavy fog in Beijing, I arrived at T3 Terminal in Beijing at midnight 1: 00, and found someone sleeping in the "arrival hall". There were also some hotel receptionists waiting for guests in T3 arrival hall.

However, I don't think this is safe.

Near Beijing airport, there are many expensive hotels, some of which have free shuttle service. Why not choose a suitable hotel and sleep for a few hours? I always make hotel reservations.

There are also rooms at Beijing Airport that charge by the hour, but the price is higher.