Open source has benefits even if you can run yourself. You can read the code for understanding/insights. Other labs could replicate/build on it.
I sure wish I had a few 100M of disposable income to train a frontier model.
> or in the future it could be useful when training is cheaper.
I do not think that physics will allow hardware getting that much faster. But maybe we will have different, cheaper architectures by then.
Unfortunately, electricity prices did not fall by the same factor, so I fear that training a frontier model will still cause a an unsustainable dent in my monthly budget.