Actually Firefox doesn't do any content blocking by default on their equivalent iOS/Android apps, i.e., see bottom 'tracker content blocking' section of https://privacytests.org/ios.html & https://privacytests.org/android.html (which is a third-party audit site).

This site also indicates Firefox Focus has content blocking holes for Google, Microsoft, Twitter, and Yandex.

And on desktop Firefox doesn't do any content protection by default, but even their cookie protection has these same holes (see 'tracking cookie protection' section of https://privacytests.org/).

Similarly, Safari blocks cookies but doesn't do any content blocking, even in private mode.