people fall in love with fictional characters in books and other media, mostly as a product of their imagined interactions with the character.

this isn't any different, it's just a AI version of it. it's still mostly imaginative fantasy at the end of the day, and it's a form of escapism from the real world.

the new yorker had an article about it where a housewife basically had AI boyfriend who was her version of Geralt from the witcher, and was using it to cope with the fact she had a stillbirth from 5 years earlier and her AI Geralt was the only one who 'really understood her' and her struggles with the stillbirth trauma. it's all entirely a fiction in her head, but it's a mechanism for self-soothing, that is relatively harmless compared to her say, doing drugs or divorcing her husband or other methods of coping that might manifest. it was basically fan-fiction with an AI agent helping her co-write.