I have used such effects in the past and although they are created in the computer, they certainly can add to the dramatic effect. (Although I still appreciate the animated drawing of effects in graphic comics.) Drawing explosions, gunfire etc. is a skill, but if you mean photographed comics such as we do here on AMMO, then it would be very hard, and probably highly dangerous to achieve any other way.
So much of "our" comics are already created in the computer anyway, ....speech bubbles, sound effects etc. (Thank you "Comic Life"!)
It's an advance in technology and here to stay, although I would prefer it was used with some discretion.
"Effects" can so easily be overdone and then they over-power the story.