Orbital Railcannon strat

Level 40 Diver here, friendly question for the high level divers and 'meta' players

Why don't people make more use of the Orbital Rail cannon for heavys such as the Charger, Impaler, bile titan , and tripod? Or use them to destroy solo Illuminated ships? It works 90% of the time as a one hit kill and gets rid of them quickly, however I see other players preferring to use other strats for them that often don't always get the job done such as 500kg bomb or a bombardment

As I'm not quite a veteran, am I missing out on a better more optimal strategy that I'm too smol brained or nooby to understand? Is there a better start that I should be using instead of railcannon? Honest question