I don’t know if I understand @archerallstars’ comment nor its context but I guess it’s this. Correct me if I’m wrong.
With Web 2.0 (participatory web) and most online services that have signup, a server stores a list of users’ “usernames” (email address, unique random integer, unique user-chosen name etc) and passwords (best practice is salt and hashing with a brute-force resistant algorithm). Many online services use email address verification as a way to prevent false account creation.
With Web3 (blockchain-based web), not to be confused with Web 3.0 (semantic web), user accounts are crypto wallets (public key is shared, private key is on the user’s device) not credentials stored on a server of an online service. Account credentials are not stored on these servers. Considering crypto wallets can be trivially mass-generated, an account’s trust may be verified by checking what cryptoassets the corresponding crypto wallet holds.
Servers of online services may of course store vast amounts of data. Posts, direct messages between users, account activity, search history, purchases via the service, IP addresses, timestamps etc. Thus I suspect it’s generally false that Web3 online services do not store user data. @archerallstars commented “Yet, you’re OK with storing your account on the web
”(post), but Web3 users must beware some data about their activities may also be stored permanently on public blockchains, something to keep in mind if you care about privacy. There are also some Web3 services that also cater to non-crypto people, thus also allow account creation by pre-Web3 methods (email, password etc), in such case the server needs to store account credentials.