first mover advantage and alot of momentum. BIG players on board.

though yeah, time will tell.

if Ethereum can't scale fast enough and EOS sweeps in and catches... could be a different matter. though, it also doesn't have to be either-or - ultimately, the greatest success will probably be had in cooperation rather than competition, and there could be some serious synergy through which both succeed wildly (consider the statement that EOS could run all of Ethereum in a single contract - not rendering Ethereum obsolete, but powerfully serving to complement and enhance it)...