Scrum is a method to allow agile development to sort-of work within a management structure that needs waterfall. It provides observability of work getting done

Scrum is a method to allow agile development to sort-of work within a management structure that needs waterfall. It provides observability of work getting done by developers, without as much up-front external design as waterfall. It's not intended to make developer's lives easier, it's entirely for management's benefit. It reduces the ability to respond to change, but in return provides management with easier scheduling. That extra scheduling is sometimes not important, but often it is. If you have external vendors or contractors they'll have their own schedules; your company will be paying them for their time whether you can keep them working or not. Predictable delivery can be very important. E.g. if you're making a hardware device, you'll have a "slot" in a factory schedule. If your firmware is late, you're still usually paying for that time slot (the factory employees still get paid), and you're paying extra to get another time slot (as well as for any downstream delays).