Maybe Bitcoin is all we really need. "Fix the money, fix the world".
Well, personally, I would not conclude that Bitcoin is all we really need, I would allow the future to decide that, this is because there is a possibility that something better might come up in the future that might cause us to start overlooking Bitcoin the same way Bitcoin has caused many of us to start over looking fiat today, after all , 20 years ago, you and i had no idea that there would ever be a currency called Bitcoin that would be digitalized, and built to be completely decentralized and free from any central control, and made to be completely borderless, that is any body from any part of this world can trade and store Bitcoin without any hindrances.
I would never conclude that Bitcoin is the last bus-stop in the evolution of money, though it takes 100 , 200 or 500 years, there's will always be a possibility that a new technology can be built.