Glyphosate is a lot safer than many organic products. Of course the later is a "chemical" with a "scary" name, while the later has great marketing and has been used for thousands of years.
However it is less harmful than most organic options overall. It is completely harmless to humans or other wildlife. It doesn't build up over time.
You are right that a so-called natural pesticide like rotenone seems to be even worse. They were able to induce parkinson with it in rats in just a few weeks. But also Glyphosate is looked at with a lot of suspicion.
Take this case study, they refer to several cases and epidemiologic research: https://pubmed.ncbi.nlm.nih.gov/30799335/
Considering the medical attention and research it gets, I see no reason to be as sure as you are. Especially your believe that "it's completely harmless" seems to have no solid reasoning behind it.