Christ, there are some dreadful comments on this thread.
Holding a baby can be a comforting feeling, for lots of different reasons. And reborns recreate this feeling, with their soft-touch finish, lifelike colouring, and realistic weight distribution.
High-quality reborn dolls are incredibly lifelike, and research suggests that they trigger a release of endorphins so can be extremely effective in boosting mood and easing loneliness.
They aren't for everyone, and that's OK. But for patients with dementia, some parents who have experienced a loss of their baby, ** or others with mental health issues like depression or anxiety, they can be extremely comforting.
(**Some parents who have lost their baby find reborns comforting, others find it upsetting).
Personally OP, I wouldn't go out and about with one because people are pricks who can't mind their own business. But for use in your own home, absolutely. You may find a reborn brings you a lot of comfort without any added responsibility, like pet ownership.
NB/I don't have a reborn doll, nor do I have any desire to have one, but I've been running a large craft group for about 14 years and the abuse the people who make reborns receive is off the scale. I've seen firsthand the joy that reborns bring to some people and I'm not about to scoff at that.