When you have your game library sorted alphabetically, some games aren’t grouped together like they really should be. For example, you might want all the Yakuza games grouped together, but the newer games are called like a dragon and are completely separate. You could now go and have the like a dragon games sorted as if they were also named Yakuza, so that all the games are grouped together.

Another example for me personally is that I have a bunch of Metroid games on my deck, and almost all of them are grouped together, except for Super Metroid and AM2R. Now I can move those to be listed alongside the other Metroid games.