I have an argument for making an action take time that doesn't hinge on realism; the first time you decide you're powerful enough to take on the whole sector at once, you pull up to a planet, order a general bombardment, the dialogue screen drops away and as the cool-up timer ticks and your fleet slowly orbits the planet, the planet is visibly raked from one side to the other with explosions, then a half-second of nothing -- just long enough to make the player feel disappointed ("that was it?") -- and then suddenly explosions scattered everywhere, like rain drops, and after another half second it begins to build -- hard -- spiking in intensity until the soundtrack cuts away to gentle screeching woodwinds (i cant remember what game does this, im sure it was either Plague Inc or Defcom but I cant find the track) that leave the player certain that, if they just listen hard enough, they can hear screams, and then another split second of reprieve from the explosions (as the planet's terrestrial defenses are completely defeated), and then, the crescendo; the planet is blanketed with a brief conflagration of explosions; devestation so thorough that from your vantage point in space, a single portion of the planet cannot be seen that isn't being blasted, and then nothing for a few seconds to let the (first time) player sink in what they just did, and why, once the dialogue screen pops back up to give a feedback report, nearly every major faction in the sector is now at war with you and how much you deserve it.
you can't do that with a dialogue screen. If general bombardment is going to function as a hard-mode button where most of the known universe declares war on you at the same time and there's no going back, I want it to be haunting. I want everyone to know why they deserve to be destroyed for what they did