Franky1 is the biggest advocate of this idea in the forum. I respect that, but it is very debatable. What if Bitcoin Cash increased its block size and doubled its monetary supply? Would that "bilateral split" idea be easy to accept? I believe it won't.
Did you mean to say
Block Speed and not block size, as BCH has already increased block size?
Doubling their amount to
42 million coins, so in a world that has
7.7 billion people,
you think that is enough to be a global currency used by all.
It is not ,
a True Global Currency needs at least a billion or more coins.US $ Fiat alone had ~
80 trillion dollars according to a CIA 2017 report.