Its one thing having a baby late in life (which is questionable)
But its revolting to have an infant child as well as young grandchildren. Family friend did this and it mentally fucked everyone up. It's far from "its just love, innit." Sibling resentment is hard enough but your life, energy, finances even mother of the baby all changes and creates all sorts of bitterness.
What's wrong at that age with being a good grandad, living a good life and indulging some hobbies? Why have a child to fuck up your existing family and quite likely cause an aching horrendous loss for your child to carry round.
And that's without the many moral problems if surrogacy.