Mythos screams of marketing hype, and nothing more. Opus 4.7 isn't really a meaningful upgrade in any sense, other than being more expensive.
Once you can see what something like Qwen3.6-35B-A3B can do... with just a FRACTION of the size of the larger models, You'll understand that the future is open weight models you can run yourself.
Same goes for companies, bringing inference onsite isn't hard, I'm actively building tooling to orchestrate it.
my quick read of the process they describe is that first they asked agents to rank files in order of potential to have interesting bugs, then they launch agents for each file in order of "interesting bug potential" and finally launch another agent for verification. (maybe i am mistaken, this is my read of this post https://red.anthropic.com/2026/mythos-preview/ )
it's not clear to me if they made just one pass over each file or made several passes for same file, but regardless, I think if you recreate roughly same process and burn 20000$ on tokens with other reasonably good model, you will find some fancy bugs too.