None use the file system in anything like the way their unix underpinning would have files be understood or organised for users. Hard to even know where your files are without asking the app to deal with them one by one. Predated phones and even Spotlight doesn’t do a good job of showing/knowing where your files are.
Files aren't physical.
import the images from both libraries (https://support.apple.com/en-us/119920)
View > Utilities > Duplicates
or use jdupes or czkawka on both directories.
This makes it a pain where you want to have a custom configuration. Like moving the cache to a ramdisk. My NVME disk is plenty fast, but rarely I want my browser cache to persist across a reboot. It's a pain to move the cache to /tmp/firefox-cache as an example (/tmp is a ramdisk on my laptop). Also a pain to backup profiles.