Backlog grooming can be done asynchronously, constantly. The PM can push a task to the top without making the developers work harder this sprint. They can go faster or get delayed, because they don't have to meet the arbitrary requirements of a sprint.
Sales use a sales funnel as their guiding organizational tool. IT operations and support do reactionary work on incoming tickets, and some rather routine and planned projects. HR is almost all routine paperpushing. Legal has to take the time it takes to answer the questions they get, because they have to answer correctly. Market analysis is timeboxed analysis - a spike in agile lingo. Hardware design is innately waterfall. Hardware production is just mindless repetitiveness as fast as you can go... and so on...
They're all different!