Beyond removing the middleman, what practical advantages do blockchain-based agreements offer over traditional ones?

Faster settlement, security through massive replication, and no counterparty risk — the agreement executes itself, so the other side cannot renege.

Three benefits come up again and again when comparing a blockchain agreement to its traditional equivalent:

• Speed and efficiency — settlement happens as soon as the transaction is included in a block (minutes), whereas a bank wire can take days and traditional securities historically settled days after the trade. There is no back-office reconciliation step, because all parties already share one ledger.
• Security and immutability — a traditional service can be taken down or altered by hacking one company's servers; to corrupt a blockchain's history an attacker would have to overpower thousands of independent nodes at once (the 51% problem), and any tampering is instantly detectable from the broken hash links.
• Removal of counterparty risk — in a classic contract you depend on the other party (or a court) to actually honour the terms. A smart-contract agreement executes itself when its conditions are met, so "will they actually pay out?" stops being a question — the risk that the counterparty walks away is engineered out.

Together these are the practical payoff of the decentralization and immutability mechanics: agreements that are not just middleman-free, but faster, harder to attack, and self-enforcing.

Go deeper:

• What is Ethereum? — ethereum.org — the benefits framing: open access, one shared ledger, and agreements that cannot be reneged on.