Part of what made Mythos so effective for Mozilla was the integrated agentic workflow where it not only looked for bugs, but then created an exploit to demonstrate them, and ran that exploit while dynamic analysis was enabled verifying that invalid memory access occurred. In this case it hard to know how much of their success was because they put more effort into the harness compared to previous tools (we know they did), or if Mythos was more suitable for this sort of workflow to begin with.
Not many apple-to-apple comparisons to be made with Mythos at this point.