Not only because of cost. Mythos has only been released to some of the big tech players because it's "too dangerous" [0] for us little people.

It's easy to see this becoming a permanent position; the latest models and smarts are reserved for establishment members only, the riff-raff get the cast-offs. So the establishment is preserved and the status quo protected.

[0] I'm putting scare/irony quotes around this, but if the reporting is accurate, there is something to this; we built the internet on string and duct tape, it's not hard to see how a very smart AI could cut it to ribbons.