Hello, Maria, and welcome! The answer to your first question is “Yes, certainly”; DC is used in authoritarian countries in which device seizure is a concern, and the issues have been discussed on the forums. See, for instance, Password or PIN protection for opening app (local data encryption) - #24 by 9er
People seem to want to hide the existence of data, resisting suspicion and social coercion, not forensics.
Searchable symmetric encryption - Wikipedia seems like it might be more useful for, say, complying with the GDPR while using a US cloud provider. But maybe I am not understanding, the concept is new to me. So I cannot answer your second question; apologies.