Gaming

They can be binding in the sense that they can govern the licensing or potentially ownership of submitted assets. So like, for example, a ToS could have a bunch of clauses that carry no legal obligation for you, but could also include a clause that grants the company licensing to use your likeness or things submitted to the server or interaction with it. The same way any ToS can license the use of your metadata for sale to 3rd parties.

That doesn't have any particular legally binding requirements of you, but it can serve as a shield in the event of a lawsuit if, say, Facebook uses your profile photo in some advertising materials.

It can also be useful if you're running a small project like an independent game server. Even if there's literally no money in it, it can be helpful to clarify who owns what in the event of something like a false DMCA. If a developer who once was doing work with you suddenly decides to take their ball and go home, some sort of agreement that outlines your ownership or usage rights surrounding code submitted to your mod can protect you when they turn around and send Steam a DMCA.

But yeah, nobody's going to get sued for using a service in a way that the ToS prohibits unless it's already illegal, like theft.