In the USA there is (was?) a tradition of ride sharing that revolved around bits of paper posted on club notice boards at airfields. Recently, some one tried to set up something along the lines of Uber to semi formalise that culture but the FAA got involved and knocked it on the head
Sorry, But the FAA Has Decided Your 'Uber for Planes' Idea Can't Fly. One result of that is that the bulletin board is now being questioned by some people.
In other countries? I don't know but I suspect it would be jumped on in the same way in countries other than the USA.