If we look at the market capitalization, ETH is 3 times ahead of Ripple. To beat the ETH ripple price should increase more than 3 times. But with this situation, ETH may also increase to some extent. So in terms of market cap, nothing ca beat ETH in the near future.
Don't say "nothing can" beat ETH in the near future in terms of market cap, better you say it "won't be easy" for any altcoin to surpass ETH's market cap in near future. Nobody can predict what happens next in crypto in future. Well I'm optimistic that ETH will maintain its second position due to its relevance in this space.