Why is the BTC trading pair more recent on CoinMarketCap than USD?

I'm curious why the Bitcoin trading pair against other cryptocurrencies like ETH or XRP appears more recent on CoinMarketCap compared to its USD pairing. This could be due to several reasons. It might be that the BTC/USD trading pair was established earlier, given its significance in the crypto market, and has been around longer. Conversely, new crypto-to-crypto pairs often emerge later as exchanges list them, which might explain why certain BTC pairs with alternative coins are newer. Additionally, the listing of pairs can depend on trading volume and demand. Popular pairs such as BTC/USD tend to be listed first and maintained for liquidity reasons, while newer crypto pairs are added gradually. The timing of listing reflects market dynamics, exchange priorities, and user interest. It's also important to consider how exchanges expand their offerings over time. The addition of new pairs often aims to cater to specific trading trends or arbitrage opportunities, leading to discrepancies in when pairs are available in different markets or on aggregators like CoinMarketCap.