You still need a centralized exchange.
Need a third party to get the money out until all-transaction is digital without any paper currency and other. I don't think compare each other right now is a good things to do, because both of them have cons & pron.
You still need both of them.
Centralized exchanges and decentralized exchanges must coexist. The assets of decentralized exchanges require users to protect their private keys or mnemonics. To a large extent, the task of centralized exchanges is heavier. In addition to protecting The assets of good users must also actively respond to hackers' theft. In addition, it is hoped that all governments will implement stricter supervision on centralized exchanges in the region to prevent the founders of centralized exchanges from doing evil.