Do we know that Fable/Mythos was the result of throwing more hardware & data at it? Anthropic is still pretty compute constrained. More does not always equal better, it very well could have been Fable/Mythos came as a result of better data curation or some other break through, not necessary more parameters & compute.

I don't think "just throw more compute at it forever" is the only way to go, but if that turns out to be true, the labs aren't going to share that knowledge because that would be a risk to the dump trucks of cash getting dumped at their feet if they came out and said "You know, we don't really need much more compute, we found a better way to make a smarter model" the cash would slow down.