According to CoinMeta, as reported by Coinspectator, the next phase for BTC and Litecoin is the first fork of Bitcoin, and Bitcoin Cash is also a fork of Bitcoin, as are Doge Coin, Bitcoin SV, etc. However, apart from Bitcoin, all other cryptocurrencies have been in a downward trend for a long time, despite belonging to the Bitcoin family. What are the fundamental differences between them and Bitcoin? There might be one or two differences, but not many. Are the first-generation cryptocurrencies the only true cryptocurrencies? Or do they include second-tier cryptocurrencies like Ethereum, which have performed worse than Bitcoin over the long term but still manage to maintain some correlation? Or will they, like the precursors of Litecoin and Doge Coin, gradually start to move in a direction that becomes insignificant? Please share your views and the reasons behind them.