Question

Correct me if I’m wrong.
The cosmological argument for the existence of God:
A. Everything we know operates causally.
B. If we go backward along the causal chain, we arrive at an infinite regress.
Conclusion:
There exists some entity to which the principle of causality does not apply, and it is a “necessary existent.”
 
Why claim the absence of causality about the entity rather than about the first point of existence itself (and thus make the entity unnecessary)?