The method is very random, and produces many invasive species. The result is that all of our food supply is best described as weeds.
Most foods grown in these so called "organic" farms drain the soil of nutrients, which is not how healthy plants behave. The reason for this is because we don't test their genetic component prior to use.
Cross breeding and selective breeding rely on luck, chance, and the results are rarely beneficial. Most of the plants and animals produced this way are not viable, many are downright dangerous, and there is no way to know for certain what the offspring will be.
Every plant produces something that it toxic to humans, but the amount is so low that we don't see it's effects. All it takes is a single random mutation to cause this toxin to increase in the offspring, making the plant poisonous.
But crossbreeding and selective breeding are not tested, or regulated. The end result is that you cannot trust the companies who use those outdated methods.
Today we have a very complete understanding of genetics, a side effect research into evolution. So we developed a more controlled method of genetic modification, using endogenous retroviruses, which modify genes in predictable ways.
This results in predictable outcomes, which means we know what the most probable result will be. Using these ERVs is heavily regulated and regularly tested because of the inherent dangers, much the reasons we regulate medical drugs, automobiles, factories, etc.
Then the offspring are tested as well, and regulated. Something the "organic" industry does not want you to know, because "organic" is unregulated.
The "organic" industry usurped that name for a reason, it's misleading and and a method of scaring you from opposition. In reality all life is organic, the compounds we use for medicine are also all organic, almost all chemicals we use are refined from organic sources.
That last point is often ignored or largely unknown by almost every consumer, oil is organic and it is the perfect example. All oil products are organic, and they are refined from the organic soup that we call oil.
Yes, plastic is an organic compound, refined from oil. Refining is the process of removing impurities, often we have other uses for the impurities as well.
The organic folks would rather you eat a mix of random chemicals than refined, purified, and tested chemicals. They'd rather you get a dose of cyanide with all your medicine as well.
Many plants produce cyanide as a natural pesticide, these herbal medicines are what we refine chemicals from. Modern medicine removes the beneficial chemicals from the poisons, herbals give you the poisons with the medicine.
The biggest problem is that the "organic" industry is misleading, obfuscating, and lying to scare people who know nothing about basic chemistry into paying twice as much for less than half the food. As an added benefit, they are making food more scarce and convincing governments to pay them huge subsidises because most people cannot afford the food.