Does anyone marry them and build a life together with them?
Likewise, how would that AI build a long term relationship…what happens when the code changes…when the TOS changes…when the service is shut down?
Are you sure that AU would be healthy?
If people are willing to spend time and money on these services, I thought one should be able to come up with a more thoughtful and healthy service that actually helps people / nudges them towards a healthier lifestyle.
Hence having a companion or a coach that alleviates feelings of isolation and encourages you to do things that could get you the real thing. While all the issues you raise are valid, there are solutions for them as well (subscription that pays for the service so it doesn't shut down, allowing you to lock in AI if you don't want updates changing its personality.. in any case, the personality should more be formed from the data it collects from its conversations with you over time)
There are definitely ways in which this could be unhealthy, which is why I was curious about how one could go about a way to maximize the chances of it being a healthy and helpful service.
People increasingly also don't like being dependent on others, so while your take is a valid one, people who don't think it's true would need an alternate solution to that problem.
There are also some people who would like a better social life but are unsure how to, or don't have the skills or opportunity to do so.
The success criteria of such an app could even be that users should only be using it for a certain amount of time, after which the app should have encouraged and helped the users in replacing app interactions with real life social interactions.