It may be incapable to solve loneliness, but it may be very capable to be a bandaid so effective, that people just wouldn't bother to deal with another people.
People talk about it as if it's a binary thing. But various people have different levels of social needs and will be receptive to AI in that manner to a varying degree.
It's clear where the average will go as it started moving with rudimentary human contact substitution technology that we had before AI.