I don't know why people care too much about total marketcap between XRP and ETH. What's benefit for you if ETH take on/overtake XRP for 2nd place again?
The only reason I can think of is that if a coin is higher up on the coinmarketcap index, then the chances of someone buying it are greater and the chances of resulting in a higher price.
What I found however is that even if a coin surpases another on CMC, it usually doesn't stay in that position for long. Remember when BCH overtook ETH last year, how long was it in the #2 spot? Not very long. Because the market-cap had little meaning when it was getting pumped very quickly and then quickly came back down.