Johnathan Helou discusses the significance of blockchain interoperability, which allows different blockchain networks to communicate and interact seamlessly, overcoming the current siloed nature of blockchain systems. He identifies the importance of interoperability for enhancing user experience, increasing liquidity, and fostering collaboration while noting the challenges such as technical complexity, security concerns, and lack of standardization. Proposed solutions include cross-chain protocols, atomic swaps, and blockchain bridges, with a vision for a more connected digital economy through collaborative efforts in the industry.