We have reached "peak UI". In the future we're not going to need every service to build four different versions of their app for every major platform. They can just build a barebones web app and the AI will use it for you, you'll never have to even see it.
I don't think this is the case. You provide an API spec but you also have to provide the implementation of that API. ChatGPT is basically a concierge between your API and the user.
I mean, if you consider mobile we might already be down from the peak. In the sense that the interface bandwidth has shrunk to whatever 2 fingers can handle.