All the sticky grenades, tripmine, incendairy, skip and scatter can all 1 shot you. I'm unsure if others can but most of the others aren't meant to, they're deterrants and used for blocking points off and still if you're exposed to one for long enough they can still kill you on their own. If you're complaining because you have received damage and then a grenade killed you whilst you were damaged you need to stop playing immediately. This clearly isn't the game for you, try Mario Kart. If you're complaining because you were hit by a grenade then tried to outgun your opponent whilst on minimal health instead of retreating from that battle you need to rethink your strategy. If you'd rather be killed by a grenade than burn for a little, jump off the side, walk out into open fire, thrown a grenade at your feet or walk out of bounds. A grenade that requires 2 other perks on the skill tree and still can't kill isn't op in the slightest, clearly you keep walking into them because you're incapable of learning an adapting.