Web3 will be a web where everyone has anonymous identity, meaning they are identified by their crypto-wallets. There is no need to authenticate yourself except once, to your crypto-wallet. You don't have to create accounts anywhere, your crypto-account is all you need.
Of course you can have multiple separate identities, meaning multiple separate crypto-wallets, if you wish.
Of course you can have multiple separate identities, meaning multiple separate crypto-wallets, if you wish.