confidential assets on liquid hide the amount you are sending and the asset type - which is a very strong privacy feature - lack of adoption make it difficult to use privately since not many people are using it

the fact that cashu and fedimint make it a priority to seamlessly integrate with lightning should reduce friction and result in greater adoption than liquid has seen - it is also a major advantage for fedimint that it will be easy to launch competing federations that are interoperable with each other using lightning