I adopted two children from the care system and it is not as easy to just learn about your past and get on with it as you suggest.
Due to my experience and knowing hundreds of other adoptive families, I would say we mess with dna and child/parent relationships because it suits the adults, not the children.
No one in the surrogacy world wants to believe that there is a problem in handing babies over to commissioning parents -with hardly any background checks. They ignore adoption practice, which used to involve similar, until everyone realised how damaging it was for the babies.
Adoption practice now centres the child and services are expected to try to maintain links with biological family by looking for family members to adopt or have special guardianship, or offering a new baby to the family who already adopted a sibling. If that's not possible, ongoing contact with members of birth family is expected, unless birth family is deemed too dangerous.
UK surrogacy allows for the child to know its bio birth parents at 18. Of course hardly anyone does surrogacy here as you can't pay for eggs or surrogates other than give them expenses.
Agencies from America hold seminars here aimed specifically at gay men. There is something very wrong imo anout a big room full of men being advised, by other men, how to exploit women for their eggs and bombs, to then walk away from both of them and never let the child know either.
Men used to have to be involved with a woman to be a father. Now they can just skip that part out. Women are redundant other than as a service provider who can be discarded.
We don't know enough about the outcomes of surrogacy like this to say that the children will be OK. There have been cases of people in their 70s bringing children into the country - we cannot assume that people rich enough to use surrogacy will be ethical about what they do.
Imo there ARE particular issues with gay and single men using surrogacy. One is that they often have dual surrogates on the go at roughly the same time - so each man has his own baby. Adam Kay and his husband did this and complained about how exhausting it was. Alternatively they get the surrogate to carry both babies, each created with separate sperm.
The impact on the women, many of whom are tricked or forced into it, or who were too naive to understand how giving up a child never to see it again, is another thing. Surrogacy risks in pregnancy are much higher. The agencies take most of the money and the surrogates get a smallish fee. Often it is husbands forcing their wives to do it.
We should see this as the patriarchy finding a new way to dominate and exploit women and children imo. What started out as an altruistic act of sisterhood has become much more sinister.