This is a dramatization of a hospital. If the show decides to depict the real hospital, no one will watch the show. It will be quite boring. IN my humble oplnion, this drama portrayed certainly things accurately and some are exacerbated
It's not that they are lazy, it is not like they have surgery every minute scheduled or something. And it usually takes really long time to perform surgeries, so it is understandable that they are resting or sleeping.