The most interesting use case of crypto to me is synthetic assets. That's where the majority of money in the trading world is stored and made.
Think of margin trading, and buying insurance on being margin called, and trading those insurance tokens - all of these are not "real" assets. They're synthetic; they've used a real asset (say, a stock), multiplied that manifold and enabled trade on it, unlocking exponentially higher value to be created.
Trouble is that this entire world is completely closed to you and I. Goldman Sachs can trade it, but you can't. You can't drop into a bank and ask to underwrite the insurance on my trading account being liquidated - only the bank can.
DeFi changes that. Any asset on-chain can be theoretically combined and made tradable. You can get a loan on DeFi platforms like AAVE. Another platform can offer insurance on those loans. And another platform can offer people the chance to bet on the insurance being called. Since everything is on-chain, a single asset can create exponential value. And since it's all decentralized, anyone can participate, not just banks.
DeFi is honestly in its infancy. The biggest platforms are barely a few years old. The idea of synthetic assets has just taken root. New platforms are just starting to explore opportunities for synthetic assets. There are some very interesting new ideas about stable currencies (look at Ampleforth, Basis Cash, Dynamic Set Dollar). There are new insurance platforms coming up where you can add money into an insurance pool and take a cut out of insurance payments.
If it works - and I truly hope it does - I can't imagine anything more exciting. The internet hasn't managed to break down the walls of traditional finance, let alone investment banks and insurance companies. DeFi is the chance to do that.
Explore this space. I used to dismiss it as just memes and scams. But the more I've dug in, the more I've realized how important it is to make money - and the opportunities to make money - free from banks.