I would argue that's exactly the point, though.
CRNAs don't cost that much less than anesthesiologists. In many cases, when they're doing locums work, or if you consider how they often don't do call or work nights or weekends, they cost more. And there's ONE path toward being an "anesthesiologist replacer" ... CRNA school. Which we know isn't a super high bar, but it's a lot higher bar than many other midlevel-ish careers.
Contrast that with emergency medicine, for which there are MANY paths toward non-physicians "working in an ER" and displacing an EM physician to some degree. You've got NPs and PAs, not to mention family med or internal med physicians who cover ERs in some places also. And then they've got urgent care centers for which there isn't a real parallel in the anesthesia world, unless you really stretch and think that setting is comparable to an ASC for us.
Anesthesiology has shades of similar problems that other specialties have with midlevels. But they're not the same. PAs, NPs, and other doctors can't do our job.
I don't know if the anesthesiology job market will go the way of emergency medicine, in terms of compensation, hours, job security, etc. Obviously there's a big parallel threat in terms of hospitals wanting to control their ERs and anesthesia departments via direct employment. But if it does happen it won't be for the same "midlevel threat" reasons.