AI is incapable of solving loneliness. It's a biological signal we have (thanks to evolution) to seek social connections with other humans , for things like reproduction and survival. Mentally healthy people will never be less lonely as long as they know they are talking to a model. All it can offer is a distraction and an illusion, because it has no humanity. Note: I don't even think dogs solve loneliness. They can…
A lot of people are not mentally healthy.
And then there's https://en.wikipedia.org/wiki/ELIZA_effect.