I don't really buy your point 2. Just the other day Meta announced hundreds of billions of dollars investment into more AI datacenters. Companies are bringing back nuclear power plants to support this stuff. Earlier this year OpenAI and Oracle announced their $500bn AI datacenter project, but admittedly in favor of your point have run into funding snags, though that's supposedly from tariff fears with foreign investors, not lack of confidence in AI. Meta can just finance everything from their own capital and Zuck's decree, like they did with VR (and it may very well turn out similarly).

Since you brought up supersonic jetliners you're probably aware of the startup Boom in Colorado trying to bring it back. We'll see if they succeed. But yes, it would be a strange path, but a possible one, that LLMs kind of go away for a while and try to come back later.

You're going to have to cite some surveys for the "most people agree that the output is trite and unpleasant" and "almost universally disliked attempts to cram it everywhere" claims. There are some very vocal people against LLM flavors of AI, but I don't think they even represent the biggest minority, let alone a majority or near universal opinions. (I personally was bugged by earlier attempts at cramming non-LLM AI into a lot of places, e.g. Salesforce Einstein appeared I think in 2016, and that was mostly just being put off by the cutesy Einstein characterization. I generally don't have the same feelings with LLMs in particular, in some cases they're small improvements to an already annoying process, e.g. non-human customer support that was previously done by a crude chatbot front-end to an expert system or knowledge base, the LLM version of that tends to be slightly less annoying.)