Interesting question. If they free range, they can hide eggs on you or a predator may get some as others mentioned. If you confine them and all they get to eat is the prepared layer feed, they will get a great balanced diet formulated to maximize egg production. That is probably your maximum possible egg production. It is what the commercial operations do.
If you confine them and feed them treats, you may cut that efficiency a bit, but it is probably insignificant unless you give them a lot of treats. Then they won't have a balanced diet with proper nutrition and their health and egg production could suffer.
If they totally free range, they will eat so much green stuff, creepy crawlies, seeds, flying critters, chunks of dead vegetative matter, whatever they can find, that they might not eat much of their layer. They will still get a pretty good balanced diet. The egg laying efficiency may drop off a bit, but you probably won't notice at all. It will be a tiny amount if there is any. The egg yolks will be darker and many people think the eggs taste better. If you are somewhere in between total confinement and total free range, your chickens may eat more layer but they will still get a pretty good balanced diet. But the nice eggs and the more humane treatment of our chickens is what makes us different from the commercial operations.
I trust you are not a commercial operation where your livelihood depends on squeezing out the most eggs you can from your henhouse full of 10,000 chickens. How you discuss it with your friend is up to you, but for me, the quality of the eggs and the way I treat my chickens is more imnportant than possibly missing out on an occasional egg. I won't say he is wrong. He may be right. But whether he is right or wrong is totally not important to me.
If you confine them and feed them treats, you may cut that efficiency a bit, but it is probably insignificant unless you give them a lot of treats. Then they won't have a balanced diet with proper nutrition and their health and egg production could suffer.
If they totally free range, they will eat so much green stuff, creepy crawlies, seeds, flying critters, chunks of dead vegetative matter, whatever they can find, that they might not eat much of their layer. They will still get a pretty good balanced diet. The egg laying efficiency may drop off a bit, but you probably won't notice at all. It will be a tiny amount if there is any. The egg yolks will be darker and many people think the eggs taste better. If you are somewhere in between total confinement and total free range, your chickens may eat more layer but they will still get a pretty good balanced diet. But the nice eggs and the more humane treatment of our chickens is what makes us different from the commercial operations.
I trust you are not a commercial operation where your livelihood depends on squeezing out the most eggs you can from your henhouse full of 10,000 chickens. How you discuss it with your friend is up to you, but for me, the quality of the eggs and the way I treat my chickens is more imnportant than possibly missing out on an occasional egg. I won't say he is wrong. He may be right. But whether he is right or wrong is totally not important to me.