I have a simple gif. I created a little less than 2 years ago to demonstrate the role of gravity in the down swing, but I can’t find the posting for which this gif. was created, so let’s just do it here and now.
In fact, it is the perfect description of what’s going on with a perfect (or as close to it as you can get to perfect) down swing action leveraged by the leading side and powered by the trailing arm.
I’m not saying you can’t swing forward, but that is not mechanically-optimal and can actually lead to mechanical-correctness issues, which of course means you’re sacrificing performance and raising injury risk.
One of the main issues of trying to swing at the target with the golf swing is that the ball is located near the bottom of the swing arc… so trying to direct force and energy at the target with the club when the ball is nowhere near that point means wasted energy and inefficiency.
When you really get it right, you’ll have the added benefit of gravity to maximize club head speed with efficient effort.
If you’re wondering why it’s so difficult to properly apply gravity in your down swing, then it’s likely because you’re interfering with it due to rotation, which is the true enemy of the so-called “gravity drop.”