Those older examples suffered from the "double spend problem" where you could spend the digital currency twice (or more). Kind of like cheque fraud.
The Proof of Work part of bitcoin (the part that consumes all that electricity) creates a consensus record so that if double spends are performed, only one of them will stick. Now double spends are a "feature" called "replace by fee."
Preventing double spends is worth millions to investors, so that's why it continues.
The Proof of Work part of bitcoin (the part that consumes all that electricity) creates a consensus record so that if double spends are performed, only one of them will stick. Now double spends are a "feature" called "replace by fee."
Preventing double spends is worth millions to investors, so that's why it continues.