I don't see any reason why Ripple should be in the top 10, let alone the top 2. The fight between Ethereum and Bitcoin Cash for the #2 spot was interesting. I think Ethereum should rightfully be #2, but would find it difficult to come close to Bitcoin in market capitalization primarily due to the network effect.
It's because XRP is not even a cryptocurrency. It's just a digital token offered by bankers. It doesn't even belong on the "cryptocurrency market cap" if the name is accurate (although this can be arguable for many other coins, but especially XRP).
Don't worry too much - as the market for digital currencies grows, there will be many different niches (privacy coins, banking coins, digital gold, etc.) that will be filled.
XRP and BTC should not compete too much, in my opinion, as long as the market cap expands.