Can you frame your question in a single sentence? Even after reading everything you wrote above, I’m not clear what the essence of your question really is.

Two hypotheses:

1) LLMs just aren't good enough

2) Making a billion dollar company is too expensive. Netflix lost money for years. Amazon lost money for years. Tesla lost money for a decade. Spotify took 18 years to become profitable. The AI companies are losing billions of dollars each month.

AI is not just disrupting companies and contributing for layoffs but it's also changing the buyers and customers.

Why build a new Google when the potential Google customers now just get their results from LLMs instead of SERPs?

How to be the next Jobs when there's no actual new product, just essentially an assistant tool?

How to create the next Disney, Netflix, Blizzard or Pixar when LLM's are still not good enough to produce quality content and many people are also starting to despise AI generated content? Art is still an intrinsic Human thing, even if LLMs are able to produce it.

So, although these LLMs are super amazing and definitely revolutionary, this whole AI/AGI hype is still a bit on bubble territory imho so I'm not really sure we'll see what you're hinting at with this generation of LLMs.

Also, wasn't AI supposed to be the last product we'd ever need to invent and then it's utopia and singing kumbaya for all eternity?

We won't need new companies, big personalities or heroes once Skynet/Hal9000/GLaDOS/Agent Smith/etc are in charge :)

Maybe there's a bit more to a company and its software than the quantity of code it generates? And maybe there's a built in moat that a lot of these companies have that takes a lot of effort (and marketing, etc) to overcome?

People don't just jump social networks because a new one exist, there has to be a compelling reason to migrate over to it. And for a lot of people, there needs to be a sufficient number of people (and probably existing friends) already using the app for them to expend the effort to start using it.

It's not like there haven't been other attempts at competitors for these over the years, and you haven't heard about them probably because none of them ever got any traction. And that takes more than just building software.

Like DuckDuckGo has been competing with Google search for years (it first came out back in 2008, it looks like), and likely is way better developed than anything someone will crank out with A.I. in a short period of time. And it still has a tiny fraction of Google's marketshare.

I'm not saying there won't eventually be other competitors to these, but it'll take more than just whipping up an MVP with A.I. in a few weeks.

AI is just not that good.

It's simple: AI can't really write software. AI is good in generating garbage code averaged from millions of repos.

Here is an example of software that can scale with a single person assuming AI can write software: a web-based alternative to Photoshop built on wasm. Figma is analogous to that and it's worth $10Bn.

AI can help you write code, but it still can't help you get customers, or attention. In fact, it makes it worse. AI helps with introducing more noise, more content, and more people clamoring for attention. It's a lemon market.