Atrazine and glyphosate were also believed to be safe to use. We now know that Atrazine causes Parkinson's and glyphosate causes cancer. Fruits and vegetables now have half the nutrition they did 20 years ago. This is due to herbicides decimating the soil fertility. The pessimists were right.
Last I heard they were still considered safe to use, if environmentally damaging, by scientific sources. Could you provide citations, so I might update my knowlege?
Similarly, my understanding was that soil depletion (caused by farming methods) and crops optimized purely for high yield (via breeding or otherwise) are problems causing nutrition drop in foods. And that neither are problems solved simply by going organic or GMO free.
The EPA uses bogus studies funded by the pesticide industry. Independent studies have found links to cancer, birth defects, and more.
https://www.scientificamerican.com/article/epa-atrazine-herb...
There is a trove of studies showing the harm so I'm not sure you're being genuine. If you really can't find anything on Google I'll help.
Another issue is that often GMO correlates with patentry, terminator seeds, IP lawsuits, and so on. But that's also a tangential issue.
The main issue is that, just like anything new, it puts us in the "beta testing in production" area, where the product being tested is "things which none of our ancestors have ever encountered, evolutionarily" and production environment is "our bodies".