I base my opinion on three court cases in the USA where evidence was borught to court that Monsanto knew many years ago about the cancer causing risks. on what do you base "this is simply a lie" ?
Scientifically, there is no good evidence that Roundup causes cancer.
https://www.snopes.com/news/2018/08/17/cancer-juries-scienti...
Here’s a better citation: IARC (the World Health Organization’s cancer research division) conducted a review with 20 international experts of all the publicly available research on glyphosate and found that it does indeed likely cause cancer: https://www.iarc.fr/featured-news/media-centre-iarc-news-gly...