Was your friend told she was donor conceived as soon as she could begin to start to understand (likely as a toddler) and does she know who her donor is/is she able to contact them?
I think some of the people against donor conception on Mumsnet don’t understand that things have greatly moved on in the UK in the last couple of decades. It is now standard practice/strongly advised by mandatory counselling in clinics here to tell your child asap that they are donor conceived (so it’s never a shock for them), and also mandatory in a clinic in the UK to have a non anonymous donor too - with the hope/expectation to have some level of contact with the donor once DC is an adult (or earlier with online help) if that is what the DC wants.
I haven’t heard of any donor conceived people in that situation having any issues with their conception (and I did a lot of research before having my DC with IVF using donor sperm in a clinic here). Personally I’m in touch online with my DC’s sperm donor already - I think a lot of donors are happier to be in contact than they were in the past as there has been lots of research into the benefits of contact/or more information for the DC, and donors know they have no chance of anonymity now.
In terms of the general thread, obviously I am in favour in principle for well informed donor conception and/or IVF - and I suspect many of the posters completely against it on here either haven’t done much research to the realities of it (in the UK currently) or have no experience of it themselves.
I have no experience of surrogacy myself so can’t be certain on that - only to say that I have read a lot of articles about commercial surrogacy that do seem paint a very bleak picture (as it does for ill informed, non altruistic egg donation too to be fair). I have no idea if the same is always the case for family/friend surrogacy or genuine, well informed, altruistic surrogacy (or egg donation) though. Unfortunately, like many of these things I suspect it is not a black/white picture and depends very much on the individuals involved - so I am glad we have strong regulation in the UK now for both donor conception and surrogacy compared to other countries.