Every PC user knows the feeling. You drag an application to the Trash, or click "Uninstall" from the Control Panel, assuming the chapter is closed. Weeks later, you stumble upon a cryptic folder buried in AppData or a stray registry key from that program you deleted last year. The software is gone, but its ghost remains.
Furthermore, modern applications are intertwined. Adobe Creative Cloud, for instance, shares licensing components across Photoshop, Premiere, and Acrobat. An aggressive uninstaller trying to "kill" Photoshop might accidentally take down the licensing service for your entire Adobe suite. killer software uninstaller
If you are the type of user who enjoys digging into regedit and knows what a CLSID is, go ahead. For everyone else, trust the native tools. Those "ghost files" are usually just sleeping peacefully, doing no harm. Let them be. Every PC user knows the feeling