system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars Rebels] Why are Corellian Corvettes, ships more or less specifically designed to engage fighters, never actually used TO engage fighters and just let themselves be shot?

Three TIE interceptors are the exact opposite of what should be considered a threat to a corvette IF THEY EVER ACTUALLY SHOT BACK.
gpt
It's because the CR90 series isn't specifically designed to engage fighters.  
It was designed as a diplomatic vessel, and later used mostly as a blockade runner or very light carrier.  It's armaments are turbolasers, which are generally better suited to attacking capital ships.  Fighters can typically evade such weapons, as famously demonstrated at the battle of Yavin.  
For ships meant to engage fighters, you're thinking Lancer-class frigates or similar.