Cosmos and Polkadot were once the most-hyped blockchain interoperability solutions, worth hundreds of billions of dollars each and promising to be the backbone of an interconnected ecosystem of chains. However, this vision never came to life as intended, and they have now fallen to the wayside in exchange for appchains and rollups on different ecosystems. Letâs explore Cosmos and Polkadotâs visions, their new competition, and if thereâs any hope for revival.