It's like these three coins (XRP Ethereum and USD Coin) are very popular in 2021 because from an analysis point of view I see the buyers of these coins are increasing, especially at this time BTC is very green in the market, and social media Twitter is also predicting three the coin by big Cryptocurency analysts and investors
I don’t know which analysis you followed. Whatever those three coins are top cryptocurrency in the market. I hold XRP for the few months but i sold this token just because of it's slow movement, It seems stable coin when i hold it. Ethereum is popular coin from a few years ago, also you know it’s second top marketcap coin.