What about all the privacy and security warnings MacOS throws up like…
I have no experience with this app or with macos, but just consider the purpose of the app. The whole purpose seems to be to fully uninstall/purge applications and the files leftover after uninstallation.
While it would be better if this functionality was built into the OS and didn’t require relying on a 3rd party, the permissions that are being requested are necessary for the app to do its job (if it can’t access the filesystem and it can’t access other apps data, it can’t really ‘clean’ what it is intended to clean).
The only permission that is a bit unclear is the accessibility features permission. With all that said, you are still right to be cautious, and you should establish trust in the software and its developer before using it, because you are necessarily giving it significant privileges that could be misused.
Some mild ‘green flags’ for PearCleaner include that (1) it’s open source, (2) the developers real name/identity is known (3) inspired in part by Sun Knudsen’s blogpost, Sun is a somewhat known earnest privacy advocate.