What's the deal with so many flights being cancelled?

The forces that have scrambled thousands of flights since Christmas Eve could ease in January, but that's cold comfort to the millions of flyers with New Year's plans.
And if 2021 has taught us anything, it’s that 2022 will likely be just as unpredictable.Here’s a look at what has mucked up flights for thousands of people this holiday season, and what could happen over the next few weeks.What happened?
Airlines weren't spared from the spread of the omicron variant, which knocked out