Is Polkadot similar to cosmos?

Could you elaborate on the similarities, if any, between Polkadot and Cosmos? I'm particularly interested in understanding how their architectural designs, interoperability capabilities, and ecosystem development strategies might compare. I've heard rumors that they share some commonalities in terms of scalability and cross-chain communication, but I'd like to get a clearer picture from your perspective as a professional in the field of cryptocurrency and finance. Would you say that Polkadot and Cosmos are comparable in their overall vision and execution, or do they diverge significantly in their approach to solving blockchain challenges?