Are decentralized services really anonymous?

We hear a lot about anonymity in decentralized services. To be honest, there is the chance that all this is just an illusion, since pseudo anonymity has been a successful way for companies (centralized) to give us the illusion of privacy. For example, some of you may not know this, but Protonmail removed their disclaimer that states they don’t log IP addresses, but somehow Protonmail is still synonymous with Privacy and secure communication. Is this also happening with decentralized services?

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