Because a natal chart is not a collection of independent labels.
The same Venus can have different aspects, sit in different houses, and exist alongside completely different Moon, Mars, Mercury, and other chart placements. That alone is enough for two apparently similar placements to function differently.
But something else matters even more: a natal chart is not a person’s biography.
Even within astrology, it makes more sense to treat a chart as a set of tendencies, tensions, and possible modes of expression rather than a finished script a person is required to perform.
Then family, culture, upbringing, education, relationships, positive and painful experiences - and a person’s own choices - all become part of the story.
So one placement can never honestly justify the statement: “This person will definitely be like this.”
And this is where, for me, the important line sits between interesting astrology and a collection of zodiac memes. A good interpretation makes a person more complex, not smaller by forcing them into another box.
If a chart reading leaves no room at all for a person’s own choices, the problem may be with the reading rather than the person.
The stars speak. The choice is yours.