The opposite of scrum isn't "just let engineers decide and get on with what they like".

In good tech companies, product managers + design + eng collaborate on how to meet a business need with a delightful product. The leaders of those orgs keep everyone aligned around a big goal and high-level milestones, but distribute as much of the lower-level decision-making and planning as possible.

That's mostly orthogonal to the processes for how a project is actually run (scrum vs informal vs plan-build-ship) and how the process style is decided (centrally controlled vs suggested vs team-by-team).