None of the cryptos are sound money ("money not liable to sudden appreciation or depreciation in value") except stablecoins on Ethereum. Bitcoin can easily lose 80% of its value in a month and no one would be surprised. Bitcoin is the biggest speculative bubble of all time. It absolutely has no utility (imagine if Bitcoin disappeared now - what would the world lose?).
Bitcoin can be sound money after the price stabilizes, which will probably take decades if it ever happens. Nothing else in the world ever could be sound money except commodity money, like gold, but I'd argue that bitcoin is better.
The actual real exciting stuff regarding the cryptos is here: https://ethereum.org/en/dapps/