That's a fair point and in some ways this might be a good option. But especially for relationships this seems like a massive danger zone to me. I already know a lot of singles in their late twenties, early thirties that have a hard time finding a partner because their expectations are far too high and their ability to adjust to another human too low. Adding these fantasies with perfect partners fitted to their specific personality is going to supercharge that and make it nigh impossible to find a human to match that.
You can obviously still make the argument that, if it makes them happy, it's fine, but users of hard drugs are also flooded in good feelings and society generally agrees that this is a problem at some point. Now, I know this is a daring comparison, but I think when we're at the point that people have their closest relationship with an AI chatbot, there might be serious social problems brewing.