Privacy just means the big corporations aren’t tracking you. Security is what keeps outside parties like hackers from tracking you.
Except they don’t. Google is good at keeping hackers from reading your emails, but they still read them. PGP can prevent Google from reading emails but it’s very limited as it doesn’t support forward secrecy nor does it encrypt metadata. Google also forbids use of insecure email clients, which is another reason why Gmail is so secure.
Security is necessary to have privacy, and I do recommend a lot of open source products, including Signal and GrapheneOS, but the reality is open source and proprietary, privacy-respecting or no, has nothing to do with security. Google Chrome and Microsoft Edge are the most secure browsers and because of that they offer good privacy from hackers and malicious websites, but they are not private in themselves. Because security is necessary, those browsers can be made private whereas Pale Moon cannot.
Sometimes the best options for privacy are the ones that aren’t committed. For example, Microsoft Office is the recommended office suite for Windows as LibreOffice is insecure. Google Pixel devices are the only secure phones and all other phones should be avoided. Stock Android is far more secure than all custom ROMs (including DivestOS which exists solely to provide harm reduction for those who cannot afford the newest Google pixel and should only be used as a last resort) except GrapheneOS and all Linux phones.