The core advantage is the same as CAT20, which is the ability to realize rich smart contract capabilities.
For example, this time: the mint condition is to lock $CAT, and the lock and NFT mint are completed together in one transaction. Such a design cannot be realized at all if the Ordinals protocol is used.

This is just one application. It is conceivable that in the future, NFT mint can design various fancy participation qualifications, such as: after minting a certain NFT, it must be locked for a week before trading is allowed, minting a certain NFT while also minting another CAT20 token, and so on.

In addition, there are some operations generated after holding CAT721 NFT, such as automatically rewarding 10 $CAT after holding a certain NFT for a period of time