BNB will be only use in their exchange especially in the new IEO that will be launch in their launchpad. I cannot see a wide usage of BNB so I cannot think whether BNB will continue to dominate other currencies 5 years from now.

Though it is a a very popular exchange and also to the IEO owners, so there is still a chance for BNB to rank up if they can also widen their marketing while thinking other ideas on how they can use their currency in a wider area.