The rise of monopolies is absolutely unrelated to how web operates. Crypto world already has monopolies with unmatched power. And you have even less privacy there, because transactions are public.
*Some transactions are public. Where Public == an Address. Wallet-Address pairings aren't public and Wallet can have many Addresses. You can have a new one for every transaction if you want. And it'll only become linked to you as a person if you withdraw to a bank.
So I think it does have quite a bit of privacy.
On any given website, you can create an endless amount of accounts revealing exactly 0 personal information. Whereas with web3 you always need to expose an address that may or may not reveal some payments info
So based on this knowledge, web3 is less private than what we have now
While it is certainly appealing that institutions no longer have the power to hold our data hostage, it is still important to ask: what does the public and transparent nature of web3 mean for our privacy?