both cosmos and polkadot share the purpose of being interoperable they have a lot of similarities but also a handful of differences

one of the weakness of cosmos is there’s a potential of traffic once it overloads because of its architecture
cosmos also have lots of competitors that might be stealing some market share

on the other hand polkadot’s technology allows for a more flexible approach depending on whatever your purpose is
something to note is that polkadot had been hacked before
it’s to see yet if they improved on their security or not