This is education, not advice
The information here is written for the general reader and does not replace a personal medical consultation. It cannot tell you what is happening in your own face, whether treatment is appropriate for you, or how much of the change you see is skin, volume or position.
Skin quality sets a limit that a website cannot measure
Thinner skin carries less support for anything placed beneath it, heals more slowly and marks more readily. How much that limits your options depends on your own skin, your healing history and the area being treated, and none of it can be judged from a page. Anyone offering a plan without examining the skin is guessing.
Descent is not a volume problem
Tissue that has dropped has moved rather than disappeared, and adding volume below it does not restore its position. A site that presents filler as the answer to a heavy jawline is describing an effect that does not work that way.
No outcome is guaranteed
Results vary with skin thickness, healing, health and medication, and with how much of the change is descent rather than volume loss. No outcome, no number of sessions and no interval can be promised, and choosing not to treat is a legitimate clinical decision rather than a lost opportunity.