Bitcoin and other cryptocurrencies can trace their roots to this earlier, privacy-focussed payment system for the internet.”

About forty years ago, cryptographer David Chaum invented ecash. Ecash is a currency privacy protocol, not a currency itself. However, the fiat banking system did not adopt ecash, leaving the ecash protocol without a viable currency to operate on. But with the advent of Bitcoin, the most open currency, the concept of ecash has been revitalized on Bitcoin. For example, https://cashu.space/

Bitcoin doesn't need ecash. Ecash needs Bitcoin.

https://bitcoinmagazine.com/culture/genesis-files-how-david-chaums-ecash-spawned-cypherpunk-dream