Nested sharing could only lower the access rights

Mostly I wonder is it a bug or feature? Is there any special reason Nextcloud work like that? And are there any changes in next releases?

Steps to reproduce

1. Create folder1 and test.txt in it;
2. Give some user read-only permissions to folder;
3. Give the same user write prmissions to test.txt;

Expected behaviour

User should be able to write into file. The closest sharing option should be selected.

Actual behaviour

User has read-only access to file.

Cause

In Cache.php of files_sharing application there is an entry:

If you change AND (&=) to OR (|=), you'll not be able to forbid user something inside the shared folder.
Is there any reason why we can't use $entry['permissions'] to the file?

Nextcloud version: 16