If there is some (not initially necessarily net for all users -- benefit being, after all, something that varies from user to users, but significant for some subset of users) benefit, the point is to mitigate the cost of moving out of a native text format, and increase the number of users for whom there is initially a net benefit, which also increases the initial use of the binary format and the effort likely devoted to building auxiliary tools which leverage it to some advantage, increasing the speed at which the net benefit of the format for a wider range of users is increased.

This may or may not ever make it a net benefit for every user, but that's okay. There's a whole lot of space between "this technology is the best choice for everyone" and "this technology is the best choice for no one".