Writing to write is like eating to eat. Neither is likely to produce a desirable result.
If there’s no idea or objective, you might as well go for a walk until something pops into your head. And, when it does, then start writing… even if you’re not putting anything on paper or onscreen; just collecting what you want to say until you have a chance to sit down at a keyboard or notepad.
At that point, you’ll know where you’re going, even if you don’t know the route that you’ll take. That’s the adventure, the discovery of writing. It’s the journey that gives you new insights and ideas (and may even cause you to change your destination).
But a starting point is rarely enough. You need to know why you decided to begin there, even if you’re starting at the end. And, once you know that, you’ll have something to say. And to write about.