Do you know that GMOs have existed since forever? They just weren't made artificially. Making a plant reproduce with a different species so it produces more fruit or the fruit can grow in a harsher weather is making a GMO. Dogs are GMOs because breeding.
So maybe ARTIFICIAL GMOs can cause harm if there is no proper research with the chemicals they are modifying the organism with.
But tbh, I don't care about eating GMOs or not. If the food had been approved by my country's ministry of health, I'll eat it without concern. And just so you know, Spain has been selected as the most healthy country in the world this year, and we do eat a lot of GMOs, so you're most likely wrong about that video you linked.