Lines from movement need botulinum. Lost volume needs filler or fat. Descended tissue needs surgery. Mixing them up wastes money.
Forehead lines, frown lines and crow's feet are creases made by muscle movement. Relaxing the muscle softens them for 3–4 months. No filler and no surgery addresses this mechanism as directly.
Hollow temples, flattened cheeks and tear troughs are deflation, not sagging. Replacing volume lifts the overlying skin passively. This is where most under-40 'I look tired' complaints actually belong.
Jowls, a heavy neck and deep nasolabial folds caused by cheek descent cannot be injected away. Filling them adds weight to tissue that has already fallen — the puffy, over-filled look that people fear comes from treating a surgical problem with a syringe.
In the thirties: prevention and small volume. Forties: volume plus energy devices. Fifties onward: surgery for descent, with injectables afterwards for fine detail. Doing it in that order costs less over a decade than repeatedly filling a lifting problem.
Repeated over-filling can. Sensible volumes replaced as they resorb do not, and that is a technique question, not a product one.