That's a great overview of DeFi sector! Don't hesitate to share your knowledge with other community members on
https://defiwiki.org/Why is DeFi called decentralized finance? If centralized Stablcoin is laid
Well, not each stablecoin is centralized. We can consider as examples of centralized stablecoins: Tether, Gemini or USD Coin. They are backed by fiat currencies or commodities collateral-backed. But there are decentralized stablecoins that are backed by crypto/multiple assets. Such as MakerDAO's DAI, Synthetix, EOSDT, etc.
https://defiwiki.org/wiki/Stablecoins DeFi is not only about stablecoins, but there are also many other components
https://defiwiki.org/wiki/DeFi_-_A_Beginner%E2%80%99s_Guide_to_Decentralized_Finance