The concept of small spacecraft or starfighters enjoyed mixed success during humanity's ascendance and dominance over the galaxy.
Swift, agile and cheap, starfighters performed fairly well as cheap weapon platforms that could harass large, sluggish targets from a distance.
In fact, humanity initially deployed drones to serve this role, but they became too prone to hacking. Any rival with a bone to pick could sneak in and sabotage the AIs controlling the drones, causing them to fire on their allies instead!
This meant that piloted starfighters actually played a respectable role during the Age of Stars and Age of Conquest.
Yet when humanity finally started to fight against the big boys of the galaxy, the downsides of fielding starfighters became very prominent.