Good point. Although they also need to make a profit. To justify an eventual PE ratio of 25 and a current valuation of $1 trillion they need to make an annual profit $40 billion. And then lets assume $40 billion in other expenses. So they need revenue of $50 + $40 + $40 = $130 billion revenue annually.

But if you buy them today at a $1 trillion valuation, and they only make $40 billion in annual profit, your investment will go nowhere. They need to be growing profits at 20% per annum to justify a PE OF 25.

And then you have the competition problem. The cheap open weight models are good enough for many (most?) tasks.

And then you have the problem that LLMs may not be that useful outside of programming, customer support and law (and doing homework).