system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do Crypto-currencies need to be 'mined'. Why can't they just be created in a certain amount and then bought and sold at a set rate?
gpt
The "mining" is really running the brains of the encryption itself. Without miners, their is no computing power to protect the currency or make it work.

That really was the novelty of bitcoin. An independent economy where helping the currency run paid you in the currency itself.