I have worked with many companies in my career, some small, some medium sized and some very large.
The ones that do well and are very successful, have detailed plans. They take the time to plan. They then follow the plan and behold they do well.
Those without plans have trouble. The wonder why they are spending so much time and energy and getting little or no results. Duh!
Can you get things done without a plan? Sure. But at what cost in time, quality and cost?
The problem with planning is it takes time and thought. Too many want to just do. But do what? Without a plan you can do anything but that won't necessarily get you to your end goal.