You may be right because Henry Ford as once predicted the existence of cryptocurrencies about 100 years ago if I'm not mistaken so it is very possible that the coib was available in the 90s but very unpopular.There used to be a currency called HashCash. It was created during the 1990s and it was no so popular at that time. I am not sure if it had any real value like Bitcoin but it had a Proof of Work algorithm.
That's more like digital gold, I guess the E-Gold was under the control of the US government which made it easier for them to close unlike cryptocurrencies that is decentralized.Before Bitcoin, there was an electronic payment system called E-Gold. It was not a digital coin per say. But the amount held in E-Gold accounts were equivalent to the amount of real gold that was held in banks. Unfortunately, E-Gold got closed by the U.S. authorities.