If another coin takes over from Bitcoin as number 1, then Bicoin's domination will be over.
ETH actually got fairly close once, but it was a blip.  XRP is in a super bubble, it will fall back down.

There is so much new money in crypto at the moment and Bicoin has been sideways/down for 3 weeks (i know how ridiculous that sounds) so people are moving into Alts. Bitcoin is still THE coin. Ripple especially is more complicated than Bitcoin and lacks most of the advantages of Bitcoin (as well as some obvious disadvantages)