Who cares about how much it filters out? The question is how much false positives does it have? And google most definitely are not good enough to even be usable

Who cares about how much it filters out? The question is how much false positives does it have? And google most definitely are not good enough to even be usable in that department. If you never know if you've missed something you have to constantly check the filtered mails as well, making the spam filtering much worse than nothing. If you rely on something as blunt as gmail spam filtering you don't take emailing seriously.