I bucketed crypto projects into two categories: (1) things that are only possible on crypto networks, and (2) things that people aren't motivated to do on other networks. For example, the US is woefully missing a banking API, especially for consumers. DeFi takes a stab at this. DeFi is still mostly closed circuit and too expensive, but if it continues to grow and integrate with non-crypto financials, that's a strong basis for a banking API.
The blockchain ecosystem has also fueled a lot of work into zero knowledge proofs and its components like homomorphic encryption, which has uses outside of blockchain. So even if the grand experiment fails (strongly doubt the whole thing fails) there will be a lot of cool technical progress that has been made alongside it.