We know that pregnancy using donor eggs (eg carrying a pregnancy that the woman has no genetic link to) has a significant set of risks associated which impact both mother and child. This includes a higher chance of miscarriage, risks of high blood pressure developing in pregnancy, 3x chance of preeclampsia, higher chance of premature delivery and low birth weight, even in young and healthy women pregnant using donor eggs, and given this information there is growing evidence that use of donor eggs may have long term health effects for the gestating mother.
A speculated mechanism for these issues is that the immune incompatibilities/differences between the gestating mother and the donor eggs accentuate the maternal/fetal immune conflict of implantation and gestation during the pregnancy. This is only emerging through research now, as prior to IVF technology being available, there was no mechanism for the situation to occur in nature.
Given that the use of donor eggs creates significant health risks for the recipient mother and the child she is bearing, and the process of simulation and harvesting during donation of eggs comes with risk to the donating mother, it seems the height of selfish indulgence to engineer this complex situation which increases risks for both mothers and the child, for a perceived social benefit/experience of bonding when the egg donating mother would be able to carry the child herself without the added risk.
We should perhaps remember that human physiology is not 'plug and play'
(Edited for stray and errant commas)