Flight attendants are covered by the Railway Labor Act. They can't actually strike. The President can forcibly prevent them from striking. There are serious penalties to be had for any kind of illegal strike.
So what's been going on instead is an "unorganized" definitely-not-a-job-action where some individual flight attendants do a bad job on service while still fulfilling all of their safety duties.
American Airlines flight attendants say their pay is so low, they fight for airplane meals to save money and sleep in their cars—and they're ready to strike ( fortune.com )