The answer is NO, 2020 still belongs to centralized exchanges, decentralized projects are very popular in 2020 but it comes with full disaster, too many DeFi projects are failing or probably get hacked easily, and DEX exchanges have too many complains and only centralized platform see less bad results this year, if I recall correctly only Kucoin got hacked
It must be admitted that DEX such as Uniswap is growing very rapidly in 2020 and the transaction value is very high, even exceeding the transaction value of several Centralized exchangers. I think DEX will continue to grow because of the easier and faster transactions.