Europe generally has much more regulation than the US, not just in food, but in all areas of life. In addition to individual counties having on average more complex regulation, the EU's main purpose is to set regulation standards between member states.

Also, from a cultural angle, food tradition is more deeply ingrained and there is much more skepticism of GMO and food products. American food has a reputation of being fake/candy.

Interestingly, the UK seems to be far more on the US's page when it comes to food and it was a component of Brexit that they wanted to right to race to the bottom on their food products.