Why do blockchains need oracles?

Oracles enable smart contracts to interact with off-chain resources. Without oracles, smart contracts can only access data within a blockchain, severely limiting their potential applications. The majority of industry-changing use cases [Use Case Link] for smart contracts require off-chain data and computation for proper execution. For instance, in Bond, we need Oracle to process our off-chain data and ultimately aggregate the results into accurate, transparent, and fair Incentive outcomes.