Skin is not a surface you can optimise indefinitely. It is a barrier with a finite capacity to absorb, and past a certain point additional product does not layer — it competes, dilutes, or occludes.
The four steps that survive every version of our recommendation: a cleanser that does not strip, a hydrator, a protectant in the morning, a repair step at night. That is the whole thing. Everything beyond it is a targeted addition, not a foundation.
Adding a fifth product should be a decision with a reason attached. 'My tone is uneven' is a reason. 'It was on the shelf' is not.
Give any new product eight weeks before you judge it, and change one variable at a time. If you introduce three products in a fortnight and something goes wrong, you have no idea which one to remove.
The measure of a routine is not how impressive it looks on a shelf. It is whether you still do it on the night you get home at one in the morning.