Where DeFi Yields come from, How are they SO HIGH and is this sustainable?

Where does YIELD in DeFi / Crypto come from? Is this a FOR REAL? Is this a SCAM?

I've had to answer many versions of this qn during the bull run of the last 12 mnths. This is a compilation of all my thoughts and how I look at DeFi Yields:
https://thediligence.substack.com/p/defi-yields-demystified

Let me know what you think!