One might think that language is a crutch for non-telepaths. If you could sense what I believe, I wouldn't need to assert anything. If you could sense what I want, I wouldn't need to request anything. If you could sense what I intend, I wouldn't need to promise anything.
But that's just not right. Maybe it's true that if you could sense what I believe, there would be no need to make assertions. But the claims about requests and promises are just completely wrong. To request something is very different from wanting it. When I request something I create a reason for you to provide it to me, a reason that goes over and beyond the reasons given by my desires. We can sincerely request things that we don't want, for instance because it is our duty to request them, and even more frequently with hold back from requesting things that we want precisely not to impose on our interlocutor with the reasons that come from requesting. Sometimes we even hold back from asking because we want to get thing without asking for it. And of course that I intend to do something does not create the kind of reason that a promise does.
A society of telepaths would still very much benefit from acts that have the reason-creating forces of requests and promises, and the reason-canceling force of permissions. Such telepaths would either need to have sui generis mental states of mentally-requesting, mentally-promising and mentally-permitting, or would need symbolic conventions to indicate when they are offering a request, a promise or a permission (maybe when I am imagining a blue patch while entertaining a proposition, I am requesting that you make the proposition true, while if I am imagining a green patch I am merely permitting you to make it true). In either case, I think, these mental requests, promises and permissions would be basically a language.
So maybe asserting is a crutch for non-telepaths. But while requests, promises and permissions could no doubt be offered more efficiently by telepaths, this would still involve something that is essentially a language.