All though it might be permitted halacally to eat food if the bugs cant be seen, it still causes “mitumum halav”
That is one reason why after the golden age in spain that produced so many gedolim, since Jews after the expolsion went to Africa and other hoter climates were affected spiritually because the food was more infected with bugs that were not always visible to the naked eye.
This way one reason given why that golden era ended.