People get comfortable, relax their boundaries and behave like children.
Kids who are well behaved outside of the home are just as naughty at home as any others. It’s because they feel safe, and for kids that’s ok.
Every work place has variations on the issues you describe, depending on the personalities of staff and how management deal with them.
In my experience, the places that have the least drama are where the management are most skilled at dealing with people. Which sounds obvious but there’s a great deal of management who don’t know how to get staff to work effectively, let alone get on with each other.
Even for non management, there’s a lot to discover about this stuff in the book The Five Dysfunctions of a Team by Patrick Lencioni.