dApps need a centralized entity which is going to be a bridge between the reality and the dApps and if you need a centralized entity, why the fuck we need dApps in the first place?
That's why Eth is a pump&dump shitcoin. Nothing more.
In some decentralized games apps, you can sell your premium item ( the item you buy from developer ) to other users using blockchain.
You won't be able to do this in the centralized game, usually the game developers will prohibit you to sell premium items to other users, thus you cannot sell it back.
And because using decentralized apps, users can freely trading their items to other users without 3rd party or developer.
This is only one of the advantages if we using decentralized app.