@drq in this form, it's a definition problem more than anything.

An alternative isn't just *to* something, it's *in* (or is it *for*? I dunno) solving a specific problem also. And YouTube's list of problems it solves is, as is appropriate for its size, uniquely large.

So there probably isn't going to be just one alternative, but many, for different purposes. Probably with some empty spots where no solution exists, and some empty spots where the problem isn't worth solving.