You're fond of taking stands. First, as companies get larger and more people work on something, process is needed to coordinate their efforts. Signoff could be part of the process, but it isn't the essential feature. More important is getting multiple contributors to work together in an orderly fashion. Second, even if the only purpose of workflow was to provide signoff, that would be pretty important.
Companies are typically liable for statements made by their employees.
If someone at PayPal puts up a personal website expressing controversial views, no problem. But if they put their controversial views on PayPal's website, we have liability for that. It might have business impact, it might anger partners, it might alienate other employees, and it might even violate laws. These things could happen unintentionally. These are things the business must have some protection against - hence signoffs.