It's not about winning over Bitcoin or Ethereum. All three of those coins/tokens have different purposes, so thinking about it as one winning over another is like asking do you think there's room for the NY Yankees to win over Manchester United? They're both sports teams, but they don't play the same sport in the same league.
Yes, centralized coins such as Ripple can win. Centralized coins could have greater market cap then decentralized coins. Ripple's success in no way impacts Bitcoin's success or Ethereum's success or the success of almost every other cryptocurrency.