What DDCC can and cannot remove
Some paths are visible because they use disk space, but DDCC cannot remove them with your current permissions.
Removable
DDCC can remove this path with your current permissions.
Shown but never removed
This path is shown so you can see where space is used, but DDCC cannot remove it with your current permissions. Some system paths are protected by macOS even from administrator tools.
The paths this applies to:
/Library/Caches/Library/Developer/CoreSimulator/Images/System/Library/Caches