It's not very surprising. There's a legal rationale behind it.

Certain classes of people are granted privileged communications.

Lawyers are permitted privileged communications with the people they represent, as those people need to be able to be honest with them about their situation. You cannot compel these communications to be handed over, and I don't believe that there's an obligation to report. The idea is that we donlt want communication to break down with lawyers, because thst causes other social harm.

Similar is also true for certain other relationships, like husband-wife.

Doctor-patient.

And I guess there priest-parisoner; priests often provide a similar counsel-and-advise role.

searches

https://www.encyclopedia.com/law/encyclopedias-almanacs-transcripts-and-maps/privileged-communication

Privileged communications exist because society values the privacy or purpose of certain relationships. The established privileged communications are those between wife and husband, clergy and communicant, psychotherapist and patient, physician and patient, and attorney and client.

These relationships are protected for various reasons. The wife-husband and clergy-communicant privileges protect the general sanctity of marriage and religion. The psychotherapist or physician and patient privilege promotes full disclosure in the interests of the patient's health. If patients were unable to keep secret communications with psychotherapists or physicians relating to treatment or diagnosis, they might give doctors incomplete information. If doctors received incomplete information, they might be unable to administer health care to the patient, which is the very purpose of the doctor-patient relationship.

The attorney-client privilege exists for roughly the same reason as the physician-patient privilege. In order to secure effective representation, a client must feel free to discuss all aspects of a case without the fear that her attorney will be called at trial to repeat her statements. Likewise, to retain the client's trust and do his job properly, the attorney must be allowed to withhold from the court and opposing party private communications with the client.

A communication is not confidential, and therefore not privileged, if it is overheard by a third party who is not an agent of the listener. Agents include secretaries and other employees of the listener. For example, a communication between a psychotherapist and patient would be privileged even if the psychotherapist's secretary happened to overhear it. In such a case, the secretary could not be forced to testify about the communication. However, a communication between a psychotherapist and a patient on a public elevator occupied by third parties would not be privileged and could be used in court.