Organisations have realised that Scrum is no good at long-term planning, estimation and scheduling.  Things that senior leaders expect of their software delivery teams.  Scrum makes no promises about completing a project on time, because it takes a short-term, iterative view of work.  Scope expands to satisfy the customer.  So either scope expands and the time allocated to the project is variable, or time is fixed, and the completable scope is largely fixed as a result.