As refugees from Basecamp 2, one feature that I've not seen in action in ClickUp that we'll miss is the ability to see all files for a given project in one place—and, indeed, all files across all projects
I believe a good place to initiate this view would be would be a 4th view button to the right of BOARD. (Please excuse the crudity of this model.)
Files for a given list, space, team would be viewable depending on what level a user is situated.
Being able to click on these files and go to the discussion(s) in which they're attached would also be fantastic.
Indeed, using search or looking for the attachment icon on tasks is simple enough, but viewing all the "things" and starting there is a really powerful way to get users to get their bearings, especially if you're coming into a project that's been going on for awhile.
Hopefully, this isn't a duplicate request. I'll take my answer off the air.