Layoffs happen at different scales within a company. Individual departments can have layoffs that aren't newsworthy. If someone's budget gets cut, they might have to layoff a number of people.

The reason the big layoffs are newsworthy is that they impact most or all of the company at once. The big layoffs are usually associated with company-wide hiring slowdowns. The individual org/department layoffs are often not really noteworthy in the context of the entire company.