For me the true benefit in doing this, is to open the possibility for users to really own their game items. Let's take World of Warcraft for example, because it's such a popular game. Users sell rare items for real money outside the game because the platform itself doesn't allow it. Also, if suddenly Blizzard decides to end the game, users will lose all their items and gold, etc. If game items are stored in the blockchain, they will really belong to users and can be easily sold on a free market. Items will now really become collectibles, because they cant be faked and users will have a proof of ownership over them, and this will revolutionize games in my opinion.
If Blizzard will decide to end the game, all those blockchain items will lose their value, because they are useless without the game. Furthermore, Blizzard control the properties of those items - on blockchain they are just strings of data, and Blizzard can change how this data is decoded on their servers - for example they can swap the model of some rare mount stored on blockchain for some common mount.
Without control over the game this ownership of blockchain assets is useless. Ability to trade in-game items for real money is a feature that must be supported by the developer, even if items are on blockchain, and the reason why Blizzard is not doing it is because they don't want to - they've tried it with Diablo III for some time, but then decided against it.
Blockchain is not panacea, you can't slap it on everything and think that you have achieved decentralization and immutability.
