Basically it's the understanding that we're all in this together and we shouldn't mess things in some way for other people purely for our own benefit. Think of it as avoiding negative-sum situations. More formally:
an implicit agreement among the members of a society to cooperate for social benefits, for example by sacrificing some individual freedom for state protection. Theories of a social contract became popular in the 16th, 17th, and 18th centuries among theorists such as Thomas Hobbes, John Locke, and Jean-Jacques Rousseau, as a means of explaining the origin of government and the obligations of subjects.
I think I'm probably more pro-revolution that most, but c'mon, really? You really think that basic rules of human courtesy are the boot on the neck of humanity?
We're talking about something much more fundamental than social norms you might call patriarchal or cis-/hetero-normative or anything like that. This is the kind of behavior that keeps you from getting punched. And most people are explicitly taught these behaviors as children, whether in pre-school / kindergarten or just by being around other children at all.
Surely we can identify much more important factors propping up the current social order.
It's both, really. A part of the social contract is that, unless there are strong extenuating circumstances, everyone is expected to obey the law of the land.
It's kind of like with sports. Both football and basketball are perfectly fine disciplines on their own, but the most fundamental rule of any game is that all players play by the same rulebook. You can't have a game if every player thinks they're playing a different sport.
The current order? I think you're overthinking things here. Were talking about social etiquette that says you should not leave your messes for other people to clean up.
Basically it's the understanding that we're all in this together and we shouldn't mess things in some way for other people purely for our own benefit. Think of it as avoiding negative-sum situations. More formally:
an implicit agreement among the members of a society to cooperate for social benefits, for example by sacrificing some individual freedom for state protection. Theories of a social contract became popular in the 16th, 17th, and 18th centuries among theorists such as Thomas Hobbes, John Locke, and Jean-Jacques Rousseau, as a means of explaining the origin of government and the obligations of subjects.