You're right that the label "certified organic" is somewhat arbitrary. But it's a moot point for most sellers at organic farmers markets because they usually can't afford certification anyway. And many of them do not use pesticides of any kind, and if they do use something like Neem oil, they will tell you.

This does not solve the systemic issue, but knowing the person who knows your food definitely seems like it would be better than anonymous food at a grocery.