I don't see how Collections are a solution to the specific request for folder-level permissions. Collections are limited to Enterprise plans only, and the grouped set of items is not the same as a folder. This critical functionality has been requested for years both in this discussion and in other community threads, so it's disappointing that it still has not been adequately addressed.
I just read through 9 pages of a thread starting in 2022 asking for Folder-level permissions in hopes of finding a way to provide access to users. Only to see that it was added in November by creating Collections but it is another 'add-on' based on our subscription? This is a basic security role need. It wouldn't take Smartsheets very long to figure out the coding, put it in place and allow their already large subscription base to be extremly happy with an extremly important functionality required and available on most other softwares straight out of the box.