Well, they're going to have to figure it out.
First, super weeds are eating Roundup for lunch. Farmers have to spray more of it every year - eventually, there's an end point.
Roundup is not just Glyphosphate - some of those "more dangerous" herbicides get added in greater quantity every year.
The long term effects of Roundup are likely to prove disastrous in many subtle ways - and for a lot of people, and many farms, the fixes will come too late.