Say OpenAI builds GPT-11 and they realize it can do 95% of their clients work. Why not hire away key people from the client or the client's competitors and start eating into their market share? OpenAI would realize if GPT-11 has this ability then Anthropic is probably able to do the same thing. The company that has the most money and credit available is going to be able to buy more compute. OpenAI and Anthropic cannot slow down unless mandated to by the government.
Can you give me an example where this would make sense, because I just don't see e.g. OpenAI starting a grocery store chain or Anthropic building a wind turbine manufacturing company.
What I can see is that some company's products become useless, e.g. translation tools, as it is something that you can just do within ChatGPT or Claude.
Also, in such a future businesses would be reorganized to use AI. That probably means less employees and reduced human complexity. The business processes are further abstracted from people making it easier for a big AI lab to move in.
If I was looking at businesses today where the big AI labs could step in I would look for businesses where they earn high margins based on intellectually complex tasks. Maybe the most pure example would be trading in the stock market since it can be completely done by a computer. Then you have areas like law which process large amounts of data but are also heavily based on relationships.