So the hierarchy generally goes like this:

• You have a game
• Then you have your patch and crack makers that circumvent the games DRM. This game and patch ingredient box is called a “release”
• Then you have your repackers like fitgirl and dodi that take a release, apply the included patch to the game, make sure everything is configured and the game runs, then compress the whole thing heavily, sometimes reducing everything by up to 50%, then break the package up into a handful of large chunks, some of those chunks being things that you might not want, making them optional to you, like the soundtrack, alternative language audio packs, etc.

Because everything is so damn compressed, a game will usually take a long time to install, because your computer is literally re-inflating the bouncy castle. A lot of people will take those install times over the download sizes of the original releases which I think clarifies most who these repackers actually serve.

They exist for people with data caps and slow internet. If you can avoid downloading languages and soundtracks you don’t want in the first place then that saves you much needed data and time. And even though installation (which is actually just decompression) takes an age, it’s still faster than terrible internet downloading twice as much.