I’d say that depends on exactly what you’re trying to protect. They’re both large American companies with control over your data and your data and metadata will end up in their respective clouds. Push notifications will be handled by Google services if you use Android, but there’s an equivalent mechanism for iOS just that it uses their servers. They handle some details differently, but I don’t think any of those options deserve the word privacy.
I’d say that depends on exactly what you’re trying to protect. They’re both large American companies with control over your data and your data and metadata will end up in their respective clouds. Push notifications will be handled by Google services if you use Android, but there’s an equivalent mechanism for iOS just that it uses their servers. They handle some details differently, but I don’t think any of those options deserve the word privacy.