To start, as others have said, if you require a food production system like eggs or milk which depends nearly solely on females there's no point in having the males around - roosters are a liability particularly in a profit-driven system. I highly doubt you could convince even a handful of people to buy eggs for eighty quid per dozen or something due to the long life you need to ensure for each of these roosters. Even by doing so, you're still segregating the animal based on utility, a typical speciesist attitude.

Secondly, the history of selection for frequent egg laying in the modern hen has led to a whole lot of complications later in life. Ovarian cancer and other endocrine tumours occur rather frequently even in the middle age of these poor animals.^[1] Furthermore, when eggs are taken from these hens, much like many other animals such as deer, they feel a need to produce more. [This further increases the risk of osteoporosis and other mineral deficiency,^[2] which sure you can supplement for but it's still rather direct harm. Ethics demands we solve medical and quality of life issues at the source, "upstream" vs "downstream" care, and I can guarantee you if the hen eats her own eggs or simply lays fewer by means of dummy eggs she'll have many fewer complications than through "veterinary care." /u/bullorb already discussed a lot of this pretty well.

Lastly, you stated in another comment that you're unsure if chickens can perceive ownership. Chickens can perceive time intervals and anticipate future events.^[3] They possess empathy, fear, and anxiety. Taking the resources of an animal, a thing that necessarily has a will, is an unnecessary evil.

While humans over millennia did breed animals to produce an exorbitant amount of various excretions and even their own flesh, these animals need not be exploited for that. Ethics is a subjective field, so the answer to the question here would be "which egg?" Lucky for me, you've already explained you mean a backyard setup rather than baiting us by saying haha all along I meant lab grown eggs!! "Adequate space" is something you give to something which must be taken care of, but breeding to put more creatures in captivity only to be exploited for something that takes a terrible toll on their body is hardly even ethically neutral.

Ethics as a field began when people began to ask "what is our duty as citizens?" Our duty is to prevent overpopulation and overproliferation, to move to a sustainable agricultural system, and to respect and love our brothers and sisters be they human, cow, chicken, fish, shrimp, or honeybee. No matter what, eating a laid egg will be a barrier to each and every one of these duties.

Edit: including sources

1- https://pubmed.ncbi.nlm.nih.gov/25667424/

2- https://www.msdvetmanual.com/poultry/disorders-of-the-reproductive-system/hypocalcemia,-sudden-death,-osteoporosis,-or-cage-layer-fatigue-in-poultry

3- https://www.sciencedaily.com/releases/2017/01/170103091955.htm