1. polygon is a cheap(as in transaction fees) knock off of Ethereum, competition good. bad from the perspective of capture value in the protocol.
2. as far as I can tell as long as one oracle doesn't become dominate that provides competition
3. Defi is enabling users value across other networks. uniswap, etc.
4. On a side note, not sure why there's not an api that encrypts an nft on ipfs and only returns the watermarked version unless you send it a fee. or your the owner.