If the public key characterize the wallet, is it possible to track all transactions of that wallet?

Question

To explain better my question, consider this example:

• Individual A is an investigator
• Individual B is been investigated

Faking to be interested B's service, individual A gets B's public key to pay for his service.

As the system is opened for everyone to see the transactions, it is possible to track all the transactions that happened using that public key, and mainly it is possible to track all the transactions with that public key from now on.

In this case, the only way to be anonymous would be create a new pair of keys for every transaction, and never centralize the bitcoins, is it right?

Answer 1

If B give out his public key, then yes , A can track all public addresses related to that specific public key.

However public key is seldom used as an receiver address nowadays.
Normally B would give A his public address.
Generating a new key-pair is anonymous, but once that key-pair is used by B it is at most pseudonymous. B will need to take additional steps to be anonymous(like using stolen credit card for funding,VPN, bitcoin mixer, etc....)