You mention that training can be suspended, which is true, but don't acknowledge that puts them behind in the arms race against both other frontier companies as well as second line cheaper providers.

Without a moat, training is an ongoing cost that they can't afford to not pay

Training is not infrastructure. It’s not capex, not “investment”. It’s really an ordinary running cost of what they do, for the foreseeable future, and it’s absolutely enormous. They couldn't even dial back training in a winner-takes-it-all scenario, because training of smaller, domain specific models would remain a way to compete.