I think you are underestimating the market for AI. The better it gets the more the market expands.
The total amount spent on salaries in he US alone is over 12T dollars.
Assuming AI becomes ever more useful and is widely adopted 500B in revenue is not that crazy.
Let's posit that that's possible, for Anthropic to get to 500B in revenue, they'd either need 100% of the market or the market has to be even bigger.
OpenAI, Google, the many Chinese labs all have products and several of them likely have better financial positions. At the moment Anthropic have one of the best models but it needs to stay sufficiently above competition for them to capture a large share of the market.
At the same time this year we've seen a move for model diversification as cheaper models become "good enough". If this IPO was 6 months ago I think it might have gone better for them.
As I understand it, AI is only really getting traction in IT and software development. It's been mostly irrelevant elsewhere overall, all things considered. That could change, but basically there's only one product that is selling. Dunno whether there is $500b/year of IT and programming to replace.
Employers are reducing AI spending, not increasing it.
You're also assuming that basically the entirety of the market would go to Anthropic, rather than other providers, which makes no sense.
You are vastly over-estimating the market for AI. The extreme majority of people would never pay a dime for it.
If you ate up that 12T dollars on AI, the economy would collapse and whoosh would go the 12T dollars.
Here's the thing though: like labor today, employers will constantly be pushing for the lowest possible price. Especially in a world where open models are 90% as capable, the cost of AI labor will quickly drop. Thats not a good thing for Anthropic or any other frontier AI lab. There's a reason most companies don't just hire the top 5% of intelligent individuals. Its really just not needed for most business.
Also another aspect: think of the most highly paid workers right now in the US and the companies they work for. Assume that normal people no longer have jobs due to AI. How are these companies going to continue making revenue to pay Anthropic? Anthropic might get a quick buck but a long term growth business is not macro-economically possible for frontier AI businesses.