I usually perform the prostration of forgetfulness (Sujud Al-Sahw) in most of my prayers; what is the ruling on that?

Sujud Al-Sahw (prostration of forgetfulness) is only prescribed in the event of forgetfulness. Performing it in every prayer without a cause is an innovation. The Prophet, peace and blessings be upon him, said: "Whoever innovates into this matter of ours that which does not belong to it, it will be rejected." This act is closer to innovation than to precaution and piety. In fact, intentionally adding prostrations before the salām without a reason invalidates the prayer due to the addition of two physical pillars, which are the two prostrations of forgetfulness.