"Somewhat predict" is incredibly different than "make a detailed plan for". I like strategic planning in 3, 6, even 12 month increments, but doing the detailed work toward those high level plans in much shorter and less static increments.
Let’s assume you have a strategy for the next 3 months. You identified / endivisioned a need in the market and came up with a reasonable solution; you locked in the budget, you allocated the resources. How many times are you going to change these in the 3 months?
But that's not the kind of plan that comes out of these planning sessions. What you're describing is more like the effort to put together organization / unit level OKRs. That is a good thing. But getting everyone together to guess ahead of time how they'll execute that solution in detail is a poor use of time in my opinion. I think the planning exercise is useful for cross organization alignment at a high level, but for individual contributors, I think it at best makes their eyes glaze over and at worst makes them frustrated and demoralized, and then once the planning is done everyone goes back to doing the actual work, which of course doesn't match the plan very closely.
