Having a standard protocol for Web3 gaming is important because it allows developers to easily code complicated games that rely on distributed cryptography for things like shuffling cards, rolling dice, and many other types of game actions (simultaneous blind moves, random number generation, etc.). These fundamentals are needed by almost every class of game.
There are multiple teams working on this but recently the Web3 Foundation recently made headways into this by doing a grant to one such project.
http://org.saito.tech/saito-joins-web3-foundation-open-grants-program/Is this the beginning of fully decentralized gaming, gambling, and casinos? They seem to also be looking into adding these features into the Polkadot ecosystem via cross-chains and NFTs.