All modern cultivars of food crops are GMOs, but not necessarily due to genetic splicing/CRISPR. Humans have been selectively changing plant and animal DNA by cross-breeding, cross-pollination, grafting hybrids and general trait selection by favoring some natural mutations above others. This leads to genetic manipulation and therefore makes them GMOs. Compare maize to modern corn and you will see no resemblance. This happened long before gene splicing and other direct genetic modification technologies came about. All domesticated dogs and cats are GMOs by breeding, but don't eat them for other reasons.