Everything after that phrase does require the blockchain though- not individually, but as a sum it would be very difficult to bring that all together in a centralized manner.
A blockchain is actually more centralised than the underlying distributed network; it introduces centralisation-related problems that wouldn't otherwise exist.
1. Being a liquidity provider to get a cut of exchange fees (https://docs.uniswap.org/protocol/concepts/V3-overview/conce...)
2. Flashloans for arbitrage (https://aave.com/flash-loans/)
3. Autonomous governance for protocol updates (https://compound.finance/governance)
4. Decentralized perpetual contracts (https://www.perp.com/)
5. Decentralized mutual insurance (https://nexusmutual.io/)
Many/all of these depend on speculation to derive value, but there's added value nonetheless