The monopolization of the seed industry through GMOs is not only a worldwide economic concern, but also a health one.
Due in part to their relatively recent inception, as well as a lack of substantial independent testing, much is not known about the possible side effects of long-term consumption of genetically modified foods.
Among the possible health effects some worry are connected to genetically modified foods are digestive issues, endocrine disruption, and possibly even gene altering.
The rise of instances of gluten intolerance and other similar digestive disorders have some pointing to GMOs as a possible environmental cause of the shift. While wheat is not a GMO, other GM crops have been engineered to withstand the weed killer called Roundup, whose active ingredient is glyphosate: https://humansarefree.com/2020/08/are-gmos-detrimental-to-health-reproduction.html