- Proof of Work isn't the only consensus algorithm, there are ones with lower computational costs, such as Proof of Stake
- See IPFS, and there are other distributed storage solutions
- One can add new ledger entries that refer to previous ones, to correct them
Aside from transparency (and note that privacy is also an option on some blockchains), the main benefit is that smart contracts can eliminate the need for 3rd parties, but still provide trustworthy transaction settlements. Third parties such as the Uber organization, or a bank. The tasks they perform can be provided automatically via programmable transaction handling on the blockchain (smart contracts). Another benefit of distributed software is that it is more resilient (in theory - the global architectures are still being developed), no central point of failure or high-value target for attack.