If you let entertainment become AI, then eventually, maybe everybody will have some weird AI generating exactly the sort of entertainment they want. They'll never feel any need to branch out or expand their horizons.

This has already happened, just not in the way you're thinking. For better or worse, television was a fairly limited and human curated experience where there wasn't always something on that you instantly clicked with. Streaming services, whilst technically human curated at some level, have endless options that are recommended to you via an algorithm (a type of AI). It is extremely easy to sit in your own little AI curated bubble (e.g. true crime documentaries, mystery shows or romance K-Dramas) and never branch out.