That only applies to things Mythos does better than Opus. Mythos is supposedly very good at things such as finding vulnerabilities, but is it better at business tasks? IN the short time I had access to Fable it did not seem noticeably better at things I tried it for (lots of small tasks).
Maybe it is better at vibe coding or finding security flaws, but at how much is it sufficiently better to be worth paying the extra?
You're assuming this export restriction won't apply to any future models. The problem is a couple of years from now when the ROW is still on Opus and US workers are on something much better.