If you're looking for a contact weed killer, you're interested in only killing some perennials and if your seed has been genetically engineered to be Roundup resistant then it's a top choice. That's virtually all soybeans but still a minority of corn and no wheat or alfalfa.
I'm old enough to have been running a fertilizer plant here in Michigan when Roundup was first introduced back in the seventies. The cost was 4x what it is now and it was mainly used as a quackgrass killer back then.
There are companies like Novartis that are making glyphosate using the original now expired patent.
Monsanto has updated the product with a slightly improved formulation. I'm enough removed nowadays to be able to tell you if it's worth the slight extra money, but Monsanto still has the majority of the market.
I couldn't find reliable market share figures, but I think Monsanto has nowhere near a majority of glyphosate market. The patent expired 25 years ago and glyphosate has since been made by many American, European and e.g. Chinese manufactures (BASF, Dow, Bayer, Syngenta, SinoChem, ChemChina, and whatever). I'm actually surprised if Monsanto's global glyphosate market share is a two digits percentage.
Thanks for clarifying.
It remains the case that glyphosate is what kills things most effectively. Anything else is just flavor