The problem we see today is that the blockchain lack privacy, interoperability, and usability, which trickles down into many other issues. That's why we're building Manta Network, an interoperable and private protocol for the DeFi stack, with a privacy-preserving decentralized exchange as our first use case. We're building it as a layer-1 solution, which means that privacy will exist in the core architecture, rather than a feature sitting on top of another blockchain. By using Substrate, we can take advantage of the interoperable ecosystem that Polkadot brings. If you want to learn more, read our article:
An Introduction of Manta Network.