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In the Last Jedi,
Holdo ran the Raddus into the First Order fleet at light-speed, doing massive damage.
Why has no-one thought of this before? Fit a light-speed drive to a cheap ship, and make your own super missile. You could even fill it with a warhead for added damage. Why is it not a standard tactic?
Not only do you have incredible tactical speed advantage (compare this to the slow projectiles as the FO fleet shot at the Raddus, and it even looks faster than energy bolts), but it seemed to ignore the shields.