Obviously not in their current state, still a long way to go but we might see this happen in the next 3 to 10 years.
The whole industry seems to be moving towards proof of stake, which is inherently more efficient than proof of work.
But tps has been progressing by the day.
Your own example of 500k tps seems a bit too high to me, right now but it certainly is attainable and in the next few years we should have tokens with much better tps than Visa. The day this happens is the day crypto-currency is ready to take over fiat.
Keep an eye open for Cardano (ADA). Still in development, and results have been slow but I would expect major achievements very soon.
Cryptos have a lot of advantages over fiat: Much harder to counterfeit, it is very easy to keep track of every single transaction and it is extremely cheap to launch a crypto-currency vs printing fiat.
Since crypto is programmable it offers some other serious powers over fiat as well, such as making it possible to pay the exact amount of taxes right after a transaction instead of having to deal with all those very confusing tax forms afterwards, and many other advantages that we are not even foreseeing today.
If you think about it, fiat is already an illusion. It doesn’t really exist any longer.
When you make a bank transfer or contract a loan to buy a house those are simply numbers typed on a computer terminal: There is no physical printing of money.
The physical fiat bank notes in circulation are an extremely small part of the electronic fiat in circulation, today. So crypto wouldn’t actually change much the way we already do things today. It would simply replace a bad pseudo fiat monetary system with a much better one, certainly more secure and accountable. Much faster as well, we could have instant money wires anywhere in the world with crypto. Much cheaper as well, all fees should see a significant reduction.
Also when I said that crypto was going to replace fiat, i didn’t mean that the current crypto-currencies that exist today will replace fiat.
What I meant was that, at some point in a near future, each government in the world will realize the advantages of crypto over fiat, and they will then move their national coin towards a newly created crypto-currency that will become the national currency of that country. It could either be based on an already existing technology (crypto-currency ledger) or they could create a brand new one that doesn t even exist today, in order to absorb their national currency. When that happens, fiat will cease to exist as a printed paper and will purely exist on its electronic form, tied to a specific ledger, governed and controlled by each government. I would be very surprised if those governmental new cryptos were decentralized, I would expect those national crypto-currenciesto be pretty centralized.
That’s where I see things going in the near future, but I could be wrong, of course…We are talking sci-fi here, after all, but it s fun to think about it