I agree with OP, the explosives feel like they hit with a wet pool noodle.
Maybe that was too mean. I do think everything feels great but with the split of the former assault medic kit to support and the focus on explosives and firepower, they feel under powered. I hit someone dead on with a grenade launcher and it did some damage and got a suppression notification. In my opinion the grenade launcher should delete someone who is directly hit. Granted I suck, I fully aknowledge that but when I have gotten good hits they felt lackluster.
I also understand there is some game dev balance magic going on behind the scenes because the GL for example shouldnt be able to completely level a building and it shouldnt be a tactical nuke. BTW the building destruction is mint. That being said I think there should be some "slider" tweaks to make the base explosives actually useful for area denial and actual damage. RPGs and GL should kill those they hit and are within a game balancing distance.