Placement matters, tension matters more, and almost everything sold for scars matters less than either.
The two decisions that set a scar’s final appearance are made in theatre: where the incision sits, and whether the closure is under tension. Nothing applied afterwards outperforms getting those right.
Of what comes after, silicone has the evidence, sun protection has the evidence, and massage from week four helps. The rest is optional. We review every scar at week six and treat with laser only where it will change something.