system
Given the following post, respond as if you're commenting on Reddit:
human
[StarWars] Why did the Empire use TIE starfighters?

The Empire seemingly was birthed from the government of the Galactic Republic, so my question is, why did the Empire forsake the Republic's fleet, which eventually evolved into the Rebellion's, and contract/design a whole new family of starfighters? If there is common lineage between the Empire's and the Rebellion's star fleet, then they became greatly divergent in the time between the Clone War and the Rebellion Era.
gpt
It's all about combat philosophy.  The TIE fighter is a descendent of the V-Wing fighter, deployed late in the Clone Wars and similar to the Delta-7, commonly used by the Jedi order.    That same V-Wing design also evolved into the A-Wing fighter, which was a popular interceptor design used by the Rebellion.

The TIE fighter is a direct expression of Imperial philosophy.  Pilots (and their ships) are considered expendable assets, to be spent however their commander might decide in the pursuit of their mission.  Their cheap cost, small size, and enormous maneuverability allowed them to be deployed in great numbers, swarming their opponents to meet their mission goals. 

The Rebellion, on the other hand, focused on quality over quantity.  They needed ships they could count on for multiple missions and repair if necessary, so they opted for designs such as the X-Wing, which was equipped with shields and life-support.  A single X-Wing should easily be able to take on a single TIE fighter, but that's why the Empire endeavored to ensure that a single TIE fighter was a rare sight.