Most of popular exchange are centralized and that's why they are trying to build up their own DEX for lesser issues regarding what the crypto community is discussing. Some of them are abusing their power to influence the market but to have total control of the market it has been said that the whales are doing it.
not all exchanges manipulated price.some of them to be honest operate their exchanges.and its proved several exchanges on korea passed audit from their goverment.its shows to us centralize exchanges not always bad.