Neither XRP nor Eth can replace Bitcoin. The highest they can get to is have a nice run in price just like they did in the early 2018. XRP getting to $1,000 is a big joke of the century. BTW, according to the coinmarketcap site (CMC) the Bitcoin in circulation is already passed 17million.
I don't think bitcoin can be replaceable. ethereum and xrp very nice in the market, they have strong support. They certainly will build their own market, because they have a different appeal.