What is the appeal of swingy weapons like Lascannons.
I have been debating this for awhile now and would like to get some more input from those more in the comp scene.
I often see people praise Melta weapons, Lascannons, etc but they seem so unreliable. Like if your hitting on 3s thats only a 66% chance you will hit, then if you wound on 2s then you have an 83% chance to wound and then the enemy will probably have a invuln of 4+ which means they have a 50% chance to save. All of that put together gives us a roughly 27% chance of getting the shot to actually deal damage, that is pretty terrible. Even if you get 2 shots that is then a 46% chance you land even 1. And lets say you have 4 shots, then you have a 76% of landing 1 shot, which is still wildly low.
So my main question is why do people take these weapons that are so incredibly swingy like sure they are nice if they hit but hitting is not the likely outcome?
And my secondary question is, what is a better option then swingy weapons for dealing with high Toughness targets.