Chickens eat their own eggs when they’re lacking protein or calcium, or they’re bored. Its not “Natural” its a symptom of poor husbandry. If a chicken is being fed the correct food it is getting all the nutrients it needs, there is no reason for them to eat their own eggs otherwise.
A Red Junglefowl naturally lays a clutch of 12 once or twice a year. Chickens are not wild junglefowl. They have been domesticated for thousands of years and have been just fine laying an increased number of eggs. Problems with laying hens only started to be a problem when production became the main goal instead of the lifespan, because why feed a hen that lays 150 eggs a year for 7 years when you could have one that lays 600 in two years and dies afterwards. Leghorns and other industrialized egg layers are a problem. Which is why its so important to focus on heritage breeds, and good breeding with a focus on health and lifespan. Considering the fact the vast majority of breeds lay far less than 300 eggs a year and live long lives, that is not very hard to achive. Most backyard chicken keepers do not have industrial laying breeds.
I don’t know what you mean by “constantly going into brooding.” Most egg laying breeds don’t go broody at all. And if they do, it isn’t “mentally exhausting” its a hormonal cycle that triggers egg laying to stop and for them to incubate all day. My hens will go broody even when there are no eggs for them to incubate. Its not emotionally draining for them or whatever u think lt is lol?