For a long time, I thought of the blockchain as almost synonymous with cryptocurrencies, so as I saw stuff like “Odyssey” and “lbry” appearing and being “based on the blockchain”, my first thought was that it was another crypto scam. Then, I just got reminded of it and started looking more into it, and it just seemed like regular torrenting. For example, what’s the big innovation separating Odyssey from Peertube, which is also decentralized and also uses P2P? And what part of it does the blockchain really play, that couldn’t be done with regular P2P? More generally, and looking at the futur, does the blockchain offer new possibilities that the fediverse or pre-existing protocols don’t have?
Cryptocurrency does work. It wasn’t so good at scaling or maintaining a stable price. Or converting between other currencies. Really, it was more of a speculative gambling or money laundering vehicle than a currency, but it can handle transactions. Both sides have to cryptographically sign the transaction (using their wallet’s private key); one side can’t just unilaterally decide that transactions happened and now it’s rich.
Edit: I realize I just addressed part of your comment. For the other part: the high environmental load was a choice, intended to be used to control how new currency is issued. There is a computational cost for maintaining the ledger, but it doesn’t have to be as ridiculous as Bitcoin/ether mining got.