I believe there will always be a file system NEXT to search. Think about it.

You're at home looking for your keys. First thing you do is ask your girlfriend if she knows where the keys are. If she doesn't know you start looking for it in a categorical way: Which rooms were you in today? Where do you usually leave your keys?

I feel like search is the convenient way and will be number one. Folders are a human's natural tendency to create backup plans in case of unexpected uncertainty.