Companies have to be a bit more farsighted than this thinking. Assuming LLMs reach this peak...if say, MS says they can save money because they don't need XYZ anymore because AI can do it, XYZ can decide they don't need Office anymore because AI can do it.
There's absolutely no moat anymore. Human capital and the shear volume of code are the current moat. An all capable AI completely eliminates both.
It's a bit scary to say "what then?" How do you make money in a world where everyone can more or less do everything themselves? Perhaps like 15 Million Merits, we all just live in pods and pedal bikes all day to power the AI(s).