I agree, but there are cells that we do not want to die, because if they die they will not be replaced (they do not divide and there is no stem cell regeneratin

I agree, but there are cells that we do not want to die, because if they die they will not be replaced (they do not divide and there is no stem cell regenerating their pool): * Neurons * Retina cells and probably many others. Another thing is cells that are dying are rising inflammation to the point it could trigger auto-immune diseases.