There are many lonely people, be it for depression, anxiety, inability to create social contacts, living in exclusion, being old and having no descendants, … They are largely invisible to the rest of the society.
Seems to me that this technology might make their lives more bearable.
Or it might make their lives even more horrible. We don't know for sure. I guess eventually we will see once the studies are done on this in a few years.
I once met one, and it is extremely depressing. He was even rich, but had no idea how to get his life in order, and nobody cared about him. A helpful AI might tell him to go to alcohol therapy, hire people to clean up his house, explain bureacracy... That would help a lot.
It is easy to be lonely, I have talked to several charismatic and very cool people who complained about how hard it is to make friends in a new city. This combined with other negative factors can cause people to fall in a hole. (Of course, people who are delusional about their AI girlfriends like in /r/replika are also sad.)