Here’s why:
The Ascendant does not just show “how people see you.”
The Ascendant signifies how you’ve entered into the world. It represents your birth, your first breath, and your first, strongest view of the world.
The 1st House rules over the head. The Ascendant can not only have a say on your facial appearance, but the overall vibe of your appearance as a whole.
The Ascendant serves as a spreadsheet for the placement of your planets. Without the Ascendant, you will not know which Houses your planets are in.
The Ascendant also sets the order of the signs ruling the Houses. The signs are in order on your natal chart, and the fact that the order can’t be changed shows that the Ascendant has a strong effect on the rest of your Houses. This implies that the rest of the Houses are connected in some way to the Ascendant.
The Ascendant is often accepted in many aspect patterns due to its important and visible effects.
The Ascendant is often used as a defense mechanism against the world as a way to keep oneself safe by covering the sign ruled by the 12th House. The defensiveness/covering of the Ascendant goes with the archetypal notion that Aries, the sign naturally ruling the 1st House is always defensive and on-guard from outside forces.
The Ascendant is often used to find one’s karmic lessons and directions in addition to the North and South Node.
The Ascendant is the start of the natal chart and is arguably one of the most important angles in the natal chart.