Ask HN: How do Layoffs happen under “for-cause” employment laws?

It's a dark time for the tech industry with lots of layoffs happening.

I'd like to understand how layoffs can happen in states/countries with "for-cause" termination. While "at-will" employment laws permit corporations to easily fire employees, how do they happen in areas with "for-cause" employment laws?

Furthermore, it seems that these layoffs are happening in nations with "at-will" employment laws. This website[1] shows that companies in Canada are also firing employees. I thought all nations other than USA had "for-cause" employment laws?

[1] https://layoffstracker.com/