We've looked at some of the key ways in which procedural generation is used in games. So now let's take a look at some of its most important benefits.
If your game world is hand-built, it's going to have size restrictions for a number of reasons. Every object needs to be placed manually, every texture/model needs to be handcrafted, and so on. All of this takes time and money. Even the largest handcrafted game's world sizes, such as those seen in The The Witcher 3: Wild Hunt and Grand Theft Auto V, pale in comparison to what procedurally generated worlds can achieve.
If a game utilizes procedural generation correctly, then theoretically, there is no limit to the world size. For example, No Man's Sky is a science-fiction game set in an infinite, procedurally generated galaxy. When you start to get really big maps however, hardware becomes a limiting factor. Areas that have been generated need to be saved to the disk in order to revisit them, and this quickly adds up. For example, to generate the biggest world possible in Minecraft, you will need around 409 petabytes of storage for the level data!
Making games is expensive. Really expensive. In fact, most AAA games cost tens, if not hundreds, of millions of dollars to make. With budgets that are this high, any option to save money is welcome. Procedural generation can do just that.
Let's say that we are working on a title that needs 100 brick textures. Traditionally, you'd have one of your artists create each brick. While they will have top quality, this will cost both time and money. Alternately, by utilizing procedural generation techniques, you can have an artist create a handful of resources and use them to generate however many resources you need to use.
This is just one example, and the same goes for modeling, design, and so on. There are pros and cons of using procedural generation in this way, but it's a valid option.
If your game world is handmade, the experience that players have is going to be fixed. Everyone will collect the same items, the terrain will be the same, and as a result, the overall experience will be the same. The defining feature of procedurally generated games is that experiences differ. There is a sense of unknown to the game, and every time you play, there will be something new waiting that you haven't encountered yet.
Let's continue from the last point. If a game is linear, without any procedural generation, the challenge is gone after you've played the game once. You know the plot, you know where the enemies will be, and unless it has an amazing story or mechanics, there's not much reason why you'd want to play the game again.
However, if your game utilizes procedural generation, then the challenge is fresh each time the game is run. The game is always evolving; the environments are always new. If you look at the games that have the greatest replayability, they tend to be the ones that give the player the greatest amount of control. Most of these games will utilize some form of procedural generation to do so.