This gets more into the political side of it.

For developed nations, we'll see Central Bank Digital Currencies slowly replace the existing financial network. You can still get your flexible monetary policy, regulatory compliance, and reversible transactions with a CBDC. The additional benefit is that now instead of having a bunch of centralised, discontiguous, and opaque services for transferring funds, now you have a decentralised, unified, and transparent network for doing this. Additionally, smart contract or smart validator functionality allows you to move some of the traditionally centralised financial logic up into this transparent & decentralised space while still maintaining all the legal protections you'd have otherwise.

Side note: I say decentralised here because ideally CBDCs will use some Proof of Authority system with the various states/provinces/counties/parishes/districts/etc each running validators. The idea here being that you still retain full control by the nation however it now becomes exceedingly difficult for any one person to manipulate the network without the consent/awareness of many other officials.

Now how about developing nations? Many of these nations lack a stable or trusted financial sector. Their people don't trust the officials, the offices, or the policies. These people are the main users of the truly decentralised networks. Of course the risk of crappy smart contracts losing your money is a risk (and assurance/accreditation programs are working to improve the visibility of well designed & operated contracts). The question however is whether that risk is greater or lesser than the risks or costs of using traditional financial institutions in these regions (if the people can even get access to them).

That said I just don't see a lot of the value in a lot of "DeFi" at the moment. A lot of it exists solely as vehicles to allow people to move more money around at a time so that they can take bigger leveraged risks on the market. Now there are useful applications in the space however many are still small and finding their footing.

The majority of supply chain/production traceability solutions and identity solutions in the space are really just two sides of the same coin and serve the purpose of providing a decentralised (or at minimum federated) source of reputation for people and businesses where the local government fails to. Identity solutions provide a means for people in these nations to "prove" their credentials/reputation to gain access to low-to-reasonable interest rate loans or prove their credentials to potential employers. Likewise they provide a means for businesses to provide a history for their products which helps them sell their products at closer to the international market rate (compared to being forced to sell to the big corporation in their region that turns around and resells to the rest of the world).

Lending and Micro-lending platforms provide a means for people in these regions to get access to loans (denominated in their local currency) at rates they would otherwise not be able to get access to. People or organisations in higher QoL/CoL nations/regions can provide liquidity to these services and users in these developing regions can slowly get access to larger & lower interest loans over time by building up their "credit history"/reputation tied to their identity. In developed nations we have systems for this already but many developing nations lack such a service that is accessible to many of their people (and that is trusted). These services still have a long way to go but as the previously mentioned digital identity solutions become more available, this space should start to see some significant improvements in usability & trust.

I'll stop at that because I've already gone way past what I intended to write up (I was also considering going into detail about decentralised good & services marketplaces) but my point being that while there's a lot of issues with smart contracts, the systems provide a means for institutions to rebuild trust by using systems that prevent or at least greatly reduce the potential for abuse or lying by those institutions (or other individuals).

TL;DR: In developed nations CBDCs unify the financial space without compromising on any features of the existing system and at the same time reduce the surface area for illicit activity or attacks on financial institutions. In developing nations however fully decentralised cryptocurrencies provide a fabric for existing institutions to rebuild the trust of their people and international trust therefore increasing their people's and businesses' access to economic opportunities both domestically and internationally.