>>9120599
BTC will probably die much sooner than that, considering the chain freeze problem.
BCH, I've heard that opinion ventured, it doesn't seem particularly likely to me, especially considering the block reward ends what, 2140 or thereabouts? At that point in time there will have been more than a hundred years worth of economic development fostered and resident on the BCH chain, and those who run it heavily incentivised to keep running it, that would be much more akin to the present situation of credit card processors, for example, small % or flat fees per transaction, but absolutely obscene volumes that make it still profitable.
That equilibrium of course once again only works if you don't artificially restrict the network throughput, so isn't a possibility for BTC.
It's the actual plan for BCH though.