I don't understand this question. How could even average-human-level AGI not be useful in business, and profitable, a million different ways? (you know, just like humans except more so?). Let alone higher-human-level, let alone moderately-super-human level, let alone exponential level if you are among the first? (And see Charles Stross, Accelerando, 2005 for how being first is not the end of the story.)
I can see one way for "not profitable" for most applications - if computing for AGI becomes too expensive, that is, AGI-level is too compute intensive. But even then that only eliminates some applications, and leaves all the many high-potential-profit ones. Starting with plain old finance, continuing with drug development, etc.
Open source LLMs exist. Just like lots of other open source projects - which have rarely prevented commercial projects from making money. And so far they are not even trying for AGI. If anything the open source LLM becomes one of the agent in the private AGI. But presumably 1 billion buys a lot of effort that the open source LLM can't afford.
A more interesting question is one of tradeoff. Is this the best way to invest 1 billion right now? From a returns point of view? But even this depends on how many billions you can round up and invest.