I think you're drawing two specious conclusions:
First, "traditional food engineering" and GMO do refer to various practices, but there is a very clear distinction of method drawn by those terms. The "traditional" method short circuits natural reproductive process to cultivate desired traits, where as GMO methods entail the direct modification of genes by means external to the reproductive process. To say that repeatedly selecting the largest head of wheat and breeding from that stock is "the same" as injecting new DNA into an organism with a gene gun is absurd in the extreme. They share the same objective, of course, but the method is wholly different.
Second, the Green Revolution was the adoption and expansion of many agricultural practices of which high-yield varieties were one important feature. Obviously, "traditional" methods can have enormous effects. For instance, turning what amounted to an edible grass into a freakish calorie battery. That said, these slow and incremental processes have at least some evolutionary safeguards built into them simply from the time it takes and the holistic, less targeted changes. Once again, we are talking about a difference of method not of objective. The fact that there was a boom of food production prior to GMO does not mean that it is the same as GMO.
here is a very clear distinction of method drawn by those terms
The question is why do you care about methods when you should care only about outcomes.
Basically: How does one pursue the truth when direct engagement with evidence is infeasible?
I came to this question while discussing GMO labeling. In this case I am obviously not in a position to experiment for myself, but furthermore: I do not have the time to build up the bank of background understanding to engage vigorously with the study results themselves. I can look at them with a decent secondary education's understanding of experimental method, genetics, and biology, but that is the extent of it.
In this situation I usually find myself reduced to weighing the proclamations of authorities: