Is the lifeline reliable?

I agree with my friend upstairs that the lifeline does not represent life, but represents vitality. Counterevidence data 1: China ancients always used words such as "longevity", "premature death" and "Shou Yuan" to describe the length of life, so if the lifeline really represents the lifeline, why not just call it the lifeline? Counterevidence 2: In ancient China, people called our lifeline "ground wire", emotional wire "antenna" and brain wire "human wire", so the ground wire of the ancient palm is not equal to the length of life. Counterevidence 3: the name of lifeline permeates western divination, but in modern times we mostly use lifeline, emotional line, brain line and so on instead. To know how long you have, you can infer from the position of the marriage line. If there is no marriage line, we must start from other numerology aspects.

I have heard that the length of lifeline does not represent the length of life. It depends on the depth of the lifeline and represents the strength of vitality.