GMO and soy free feeds are not only not drastically inferior, they're not inferior at all.
They're just made up of different ingredients. Throughout the world, chicken feeds are made up of all sorts of ingredients that are available locally. We grow a lot of corn and soy in the US. So that is what the primary ingredients normally are. Peas are less available so add to the price. Monsanto pretty much corners the market on corn and soy seed so about 90% is GMO.
Globally, corn is the most commonly used energy source and soybean meal is a common plant protein source.
However, other grains such as wheat, sorghum, canola meal, peas and sunflower meal are widely used in some countries.
That doesn't make them inferior. In the US, besides energy, yellow corn adds carotenoids to the feed to make the yolks more yellow.
In most regions of Asia and Africa, there isn't enough corn production to meet the needs of human consumption so they use other cereals and seeds. What corn is fed to poultry in Africa is white and the result is egg yolks that are very pale. That doesn't make them inferior either.
Asia produces one third of the world's broilers. How can they do that without feeding GMO corn?
The US is the #1 poultry producer in the world followed by China, Europe and Brazil. Mexico, India, Japan, Argentina, Thailand, Canada and Russia round out the other top producers.
It doesn't matter what the primary ingredients are as long as the end result analyzes out to contain all the nutrients chickens need at the proper ratios. Yes, corn is a good energy source but wheat, barley and low tannin sorghum come close.
If the feeds didn't have the same analysis in regards to amino acids, fats, minerals, vitamins and energy as conventional feed for the intended age bird, they couldn't really call them complete chicken feeds could they?
Soy free feeds usually replace the soy with peas as the legume of choice.
For the cereal portion, rather than GMO corn, they usually contain wheat and barley.
Many include fishmeal to get the essential amino acids missing in vegetative sources. Conventional corn/soy based feeds must add synthetic lysine, methionine and sometimes tryptophan to make up for what's missing in those ingredients.
With all that in mind, GMO and soy free feeds would be considered superior by most consumers.
They are more expensive and if one is buying Scratch & Peck, Azure Standard or comparable organic feed then it may be 2.5 to 3 times the price but there are other manufacturers that sell comparable products at about double the cost. They are just hard to find since most feed stores only sell conventional.
Once one pays for shipping, if it isn't available locally, that could bump the cost to 4 X.
Of the total cost of feed, 95% goes to meet the energy and protein needs. 3-4% goes to major mineral, trace mineral and vitamin content. The other 1-2% goes to other additives like binding agents.
I know a Chinese woman with 3 chickens and soy-free/GMO free is so important to her that she drives from Missouri to Indiana to buy her feed.
To each his own. People should feed the type of feed that they want to. I prefer organic but often it isn't available. Since I usually ferment my feed, I'm not fond of the soy free since it doesn't wet well and it takes a lot more mixing.