As centralised exchanges (CEXs) have a central body managing user accounts, they can easily be compromised and hacked from a single point. Decentralised exchanges (DEXs) on the other hand, improve user safety by empowering users to be in control of their own funds. They also offer a high degree of anonymity and do not require users to submit as much personal information in comparison to CEXs.
DEXs do not have a single point of failure either. Any rollouts or updates occur on a node-by-node basis, meaning that even if individual nodes go down due to issues like maintenance, the remaining nodes remain unaffected and will continue to keep the DEX live.