system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does installing files take longer than uninstalling files on computers?

I had the Anaconda program used for programming platforms like Python but recently uninstalled it. I noticed that the uninstall took < 5 minutes whereas when I first installed it, it took ~20 minutes. 

It led to me questioning why installs take far longer than uninstalling programs from your computer, especially if the files are hold data in the GB range.
gpt
Uninstalling, or just generally deleting files, is a very quick operation. Instead of actually removing the data from the disk, it just removes the file from the filesystem and marks the space where it used to live as available for reuse. This is why you can "undelete" files. You just have to figure out which blocks on the disk used to hold the file and recreate the directory entry. You have to be quick though because some other file might get written over those blocks.