I missed another howler.
You are absolutely correct in saying “ Since the late 1990s, there appears to have been a net increase in total pesticide use for GMO corn, soybeans and cotton in the U.S.” and you are also correct when you state “ While insecticide application was down for crops using Bt traits to combat insects, this was apparently offset by a substantial increase in total herbicide use on U.S. croplands“ but then then you say ”…, likely because more weeds have become resistant to Roundup”. Roundup consumption increased well before any weeds became resistant to it and that was exactly the desired effect. The whole point of RoundupReady is to allow more weeds to be killed by applying more Roundup without killing the crop.
Insecticide use decreased and herbicide use increased because that is how the two technologies, respectively Bt and RoundupReady, are designed to work. Their universal adoption wherever other forces have not blocked them suggests that both have been spectacular successes.