The trough of disillusionment is going to be frightening, and I believe we're starting to see the first signs of it (with Apple's paper, ironically enough).
What really happened: LLMs are fuelling the phishing and scam industry like never before, search engine results are shittier than ever, every other website is an automated LLM generated seo placeholder, every other image is ai generated, students are heavily using these techs for homeworks with unknown long term effects, scientists are using them to write their papers: quality--, quantity++, bots on social media increased dramatically and probably playing a huge role in social tensions. You can probably add a few dozen things in the list
Remember the Metaverse? We are talking about entities that can burn billions on speculative projects and it is just a rounding error on quarterly profits. Let alone that frequently the outlay is in-part recovered via the various "sell shovels in a gold rush" strategies.
This is what total stranglehold of a critical sector helps with. Inefficiency of capital allocation at interplanetary scale - but that's another story.
LLM's might be new but the ML/AI type of efficiency/productivity argument is decades old. The domains where it leads to "gains" are generally when the org deploying algos manages not to be held responsible for the externalities unleashed.
Companies having more money than god and spending it speculatively at least got us self driving cars
Your point 2 seems to indicate that the potential for impact is huge. People also think of positive impacts, not only negative ones, that's why they invest.
They invest because greedy mfers don't want to miss the next apple or google. They'll throw millions at the walls and see what sticks, remember juicero and theranos ?
Compare this with firms that had an actual working product (ex: Lightbulb, Internet, Windows, iPhone) and not the mimics of one (ChatGPT, Bitcoin, Metaverse, Nanotechnology, Quantum).
PS: There is just too much money in the economy now (infused from covid), so chasing speculative investments is expected.
Apples share price has taken a bit of a fall this week.
https://en.m.wikipedia.org/wiki/Gartner_hype_cycle
I'm not sure how accurate it is overall, but there are companies that fit it.