Security ≠ Privacy

Security is not privacy, and don't let clever advertising convince you otherwise!

Security is the integrity of a given place or device against attacks, viruses, or other undesirable content. Privacy is if the information stored is only accessible with your permission. You need security to protect your privacy because otherwise malicious actors could break in without your permission and gain access to your information.  

However, security on its own does not guarantee privacy!  I can use Microsoft Windows, and ensure Microsoft Defender is enabled, but Microsoft will still sell my personal information to other companies. It's still secure!  People often buy security products because they increase security (like a Ring doorbell), but might not improve, or may even impede, your privacy (like a Ring doorbell sharing video with the police).  Isn't privacy what you really care about?

TL;DR: You can have security without privacy, but good security is necessary for privacy.