Why do some of you use DDU to clean install drivers?

[Wagnard]

I'm curious as to why some of you go to such great lengths to scrub the current driver off the rig.

Does the NVidia installer's "clean install" not do its job?

Is there really any harm from not using software like DDU, and just "dirty" installing?

I'll say,for normal users, use DDU only when it's needed when the NVidia installer fail or if you have some ODD issues after installing a new driver.