I don't know that "parasocial relationships" are the primary reason people like having real hosts. I have a huge list of things I've managed to change in my life because I heard some other real person talking about how they were possible. Listening to these people over time and realizing there's nothing about them that's so special that it makes things possible for them that aren't possible for me gets me off my butt to set about the hard work of making the changes I didn't otherwise realize were possible.

IMO, a lot of the best podcast content comes from a spontaneous tangent. You’d lose those moments with autogenerated podcasts.