I appreciate your point and I learned something new from it, but I disagree with the last part. By your GP's own admission, pesticide overuse doesn't threaten all of humanity like antibiotic overuse does. So no, they are not "as right as" someone trying to avoid contributing to the antibiotic overuse problem. Not all problems are equally important.

He would be wrong because animals grown for meat also eat vast quantities of of plants, which are of course grown with pesticides. So eating a plant based diet reduces the amount of antibiotics AND pesticides used globally.

Bioaccumulation of pesticides in animal tissue is a serious problem.

I do not think you can ever consume the same amount of pesticides by eating plants if before that you ate nontrivial amounts of chicken, chicken eggs, beef, milk etc. Cow eats several tons of plants in its lifetime. I'm pretty sure human comes no where close. The bioaccumulation happening there is a serious issue.

That stuff is filled with bioaccumulated pesticides.