True.
Thank you for the engagement - it is nice, even if it gets a bit testy to not have someone just walk away, and I apologize if I was out of line at times.
I think ultimately, the last few years have made everyone first defend whatever it is they believe, opposed to embracing and really considering something else. I know this is certainly true for me.
For me, my family and flock - mixing my own feed is best

We will leave it at that.
Have a good day, and ill see you around.
Defending one's beliefs, even in the face of contrary facts, is very human. There is NOTHING new about it. For many, those beliefs comprise a substantal portion fo their worldview, the way in which they define themselves - and their defense can take on an almost religious zealotry.
For what its worth, I find the emphasis on "simple" (pronounceable) ingredients, generally few in number, and as close to "heritage" (whatever that word is supposed to mean) as misplaced. Overwhelmingly, I find those that mix their own feed to vastly overestimate its nutritional character, and only consider a couple of nutritional targets (assuming they consider anything more than crude protein and calcium). In thousands of posts, I've seen two "made at home" recipes that you can populate with average nutritional values from a reliable source and have it pump out what most would consider acceptable numbers. I've helped posters in unique circumstances develop two more, with the caveat that we were only looking at a handful of nutritional factors.
Even if you grow it yourself, unless you have it assayed, you can't know what the nutritional values of any particular crop are. At best, you can rely on broadly reported averages, accepting that what comes off your soil may be consistently substantially better, or substantially worse, across a host of nutritional metrics than the average. I.e, if your soil is low in selenium, your crops will be low in selenium, and your feed will then be low in selenium. Consistently. Otoh, if you plant a high protein wheat crop, or a low tannin pea crop, chances are good your crops will better the averages for those metrics.
Neither, unless you are in quite rare circumstances, can you grow it all yourself. There's no one magic plant ingredient that makes a complete chicken feed. Soils that are good for for raising more than one or two of the best crops for filling the majority of a feed are largely in the hands of commercial scale producers. Even if you can, you then need to be able to store it. How much do your chickens eat each month? How long is corn in season? Wheat? Soy? Where and how will you store those crops when they aren't in season, so you can keep them fresh, mold/mildew free, away from sunlight, and to keep their fats (with their fat soluable vitamins) from going rancid.
Modern efficiency is based on modern specialization. You can't compete on a cost basis, and absent unusual circumstances (a large farm with heavy equipment on good soil with good climate) its impractical to try and grow it all yourself.
Buying from
Amazon, Polouse, Eden, Great Mill, Pleasant Hill and all the rest are fine (if expensive), but don't tell yourself this is your SHTF plan - because when that happens, you can expect quick shipping and ready availability to become a memory - as we just experienced.
Mills, on the other hand, do have crops assayed (at least the good ones), and do alter their mixes to provide a seasonally consistent product, adjusting for lower quality corn, or higher protein soy, or excess moisture in the wheat, or whatever, plus the multivitamin mix of course, to guarantee they at least hit various minimums. They do have the means to store whole grains in quantity for use through at least brief supply interuptions. You still have to choose a good product from a consistent mill of course - every mill is not the same, just as every chicken breeder is not the same, and every breed of chicken has its own character. But at least you have a label with some agreed to measurements.
Is that to say you should only, ever feed commercially bagged feed? No - though many peoples birds would be better off if their owners did just that. There is room in this big wide world for unique answers to unique circumstances. There's also room for educated risk taking - people like me who have done the research and feed a mix of high nutritional quality commercial feed together with free ranging in an intentionally planted polyculture. There's even room for people who have decide that unsupported, 100% free ranging is "good enough" in their climate without pretending its the best or only way.
"I only feed my birds ingredients I can pronounce that I mixed (and perhaps grew) myself, because it sounds good???" Your birds, your property, your choice. Says more about the limits of one's vocabulary than the depth of their nutritional understanding.
On the basis of nutritional comparison - which is all the bird's health really cares about:
"Best?" - almost certainly not.
"Consistent?" - definitely not.
"Complete?" - likely not.
How about?
"Comparably Priced?" - again no.
"Good for social approbation from those who likely know less about chickens than you do?" - Yeah, that. Its very good for making some feel good about themselves. But that really doesn't matter to the chickens.
Go ahead, put your recipe up. Maybe it will be the fifth reasonably successful "make at home" feed recipe I've seen posted on BYC in the past couple years.