Thank you for sharing!

Because you need an incentive for 'miners' to participate in transaction processing.

Main functionality is transactions which are not controlled by any single entity (like the government).

Most of it is speculation unfortunately, which gives it a bad name, drowning out real usecases.

Think of it this way: If you pay with physical cash, there are people somewhere who do the work of digging ore out of the ground, smelting it, shaping it into coins, cutting and printing paper and so on. All these people do that, because they get paid in the same currency that they themselves have minted.

It turns out that nobody has yet found a way to create a digital decentralized currency that that works without incorporating a similar concept of incentivizing the creation of currency.

Monero is similar to Bitcoin Cash, a useful replacement for cash in most cases.

Normal cash is just printed out from thin air by those who have the power. In that sense (some) cryptocurrencies are better because at least the process is open.

This is how money works. If you use a medium of exchange and unit of account for goods and services then that medium must increase at the same rate as the increase in goods and services otherwise you get second and third order effects such as inflation, contraction, rising unemployment, etc., directly impacting its ability to act as a unit of account.

In Bitcoin you don't generate cash, you earn block rewards for acting as a consensus broker which otherwise would require a central banking settlement layer. This activity, tied directly to the transaction layer, acts to maintain the equilibrium between increases in goods and services and expansion of the money supply.

Wall Street got ahold of it and now Bitcoin is primarily acting as a Store of Value for the purpose of speculative investments. Driven primarily by the fear of missing out and market manipulation since Bitcoin is heavily centralized.

Cryptocurrencies allow market participants to communicate value to each other without having to trust other market participants or an institution. Mining verifies transactions and commits them to the public record, earning the miner a fee for their work.

For a state or central bank the answer is obvious: The state or bank itself prints it.

For a private actor the technical means is perhaps less obvious, but the actor behind the currency obviously gets to decide.

For a decentralized open source project, it is less clear. You could do it so every node in the system gets a piece of every newly printed unit of currency, but if it is free to run a node everyone could just run a billion nodes and take all the currency for themselves.

Bitcoin solved the problem with Proof of Work, which is elegant because both the double spend problem and the minting problem is solved together. Every node has to prove it has run a unit of useless computation and inflation is spread evenly across worker nodes. This led to a split between nodes and miners with the use of specialized hardware, but the basic premise still holds.

Crypocurrencies in general are very different. Ethereum, the second most popular, was created by a private actor and the that actor decided to print 72 M for themselves and promptly sold 80+% before the release of the software which gave rise to the term ICO which was very trendy for several years. After the initial release inflation continued according to the miner model.

> why does it make sense that people can "generate" cash by proving some amount of work done? This of course cannot be done with normal cash.

People do generate money when they work, in a sense, because money doesn't have value. Money represents value. To really understand that you need to think about what money is and why it was invented in the first place.

Before the invention of money there was only direct exchange; I do/give something for/to you and you do/give something for/to me in return. But what if you want what I have but I don't want what you have? Or what if we want something from each other but are too far apart to make the exchange directly? Well, we find a third participant who can act as a kind of transfer agent. They could, for instance, have something I want that you don't want and also want something from you. They trade with you first so now you have something from them that you don't want that you can then trade to me for the thing you want, and everyone is happy. This extends to arbitrarily many, dozens or hundreds even, of intermediate steps.

Now it should be easy to recognize two things:

1) Everyone needing to store a bunch of stuff they don't actually want just so they can pass it on to the next person can become a huge burden for everyone. And how do you store labor anyway? You can't. You can only store goods.

2) Organizing dozens of intermediate links is an extremely difficult problem to solve just so you can get what I have.

The first one can be solved by exchanging IOU vouchers instead. The holder of the voucher becomes entitled to the thing that hasn't yet been given or done. Storing those vouchers is trivially easy compared to storing the things. And you can just as easily store vouchers for work that hasn't been done yet as you can for goods that haven't been given yet.

The second one can be solved by saying what if people put their vouchers into a central voucher bank instead of passing all their vouchers around to each other directly, and then the central voucher bank organizes all the intermediate steps for people without people needing to figure out who has the vouchers they need to complete the chain.

And then once you're there, why even use specific IOUs at all? Why not have all the vouchers be generic but you get different amounts of them instead of different kinds that you can then use freely for anything? And that's obviously what money is.

And from there a new thing should become obvious: The money itself doesn't have any intrinsic value. The labor/good behind it does. Money is just a way of representing the value of something you did/produced in a form that can be easily traded for other things. It's the medium of exchange, not the product. And when there are fewer vouchers in the system relative to what's being produced, each voucher becomes worth more (deflation), and vice versa (inflation). And then the government literally prints and destroys vouchers as needed to try to keep a balance. That is a thing that happens. And so what if there can be prolonged time delays between you doing your work and you receiving your vouchers under some systems? Time delays are not inherent, just practical for bookkeeping. And when long time delays are not practical for bookkeeping they become shorter.

> Are cryptocurrencies supposed to be a potential replacement for real life cash? This was my understanding of the motivation behind Bitcoin, at least.

Only as a pretense. The reality is that a currency needs to be moderately inflationary to be useful as a medium of exchange of goods/services because otherwise there's a powerful incentive to just hold onto it because it will always be able to buy you more in the future than in the past.

But solving the problem of how to transfer value trustlessly and anonymously, instantly anywhere in the world is one of the biggest breakthroughs since the Internet.

Amazing how in a few short years kids started growing up with Bitcoin and don't understand how it work or why it exists :(

I can use my compute and energy how I like, whether that’s for AI or crypto or a Minecraft server. You don’t have a right to call one “wasteful” and one not