There is no clear advantage to multiple corporations or nation states each with the potential to bootstrap and control AGI vs a single corporation with a monopoly. The risk comes from the unknowable ethics of the company's direction. Adding more entities to that equation only increases the number of unknown variables. There are bound to be similarities to gun-ownership or countries with nuclear arsenals in working through this conundrum.
You're talking about it as if it was a weapon. An LLM is closer to an interactive book. Millennia ago humanity could only pass on information through oral traditions. Then scholars invented elaborate writing systems and information could be passed down from generation to generation, but it had to be curated and read, before that knowledge was available in the short term memory of a human. LLMs break this dependency. Now you don't need to read the book, you can just ask the book for the parts you need.
The present entirely depends on books and equivalent electronic media. The future will depend on AI. So anyone who has a monopoly is going to be able to extract massive monopoly rents from its customers and be a net negative to the society instead of the positive they were supposed to be.
I would argue the opposite. Keeping AGI behind a walled corporate garden could be the most dangerous situation imaginable.