Even though bitcoin can be used for purchased in web3 but bitcoin is not the pre-dominant cryptocurrency of web3.
Take note Bitcoin that can be purchased in web3 is a fake Bitcoin since it's an unknown coin pegged with Bitcoin price and run in unknown network. If the creator or hacker have a control over the smart contract, they can rob your coins even it's not on centralized exchange.
Remember, there's only one Bitcoin in this world, it's Bitcoin (BTC) not BCH, BSV, WBTC, etc.
I don't think web3 projects on altcoins sooner or later will be vanished just like ICO, IEO, IDO, DEFI, NFT, P2E hype.
bitcoin is digital currency combines with web 3 provides more control to people without dependency on third parties
Bitcoin itself already avoiding third parties without web3.