Chainlink is centralized, decentralized oracles are an UNSOLVED computer science problem.
if you need to bring outside data into smart contracts, there are many centralized solutions.
LINK is supposedly the only decentralized solution, BUT decentralized oracles are an UNSOLVED computer science problem.
The biggest threat are sybil attacks which basically is one person/one party creating multiple identities to compromise any decentralized reputation system. Think sockpuppets, or fake accounts for farming upvotes/likes.