What we have is the M72A1 LAW(Light ANtitank Weapon, which is a one-shot weapon weighing over 5 pounds. To carry multiple LAW rounds, you have to carry multiple launcher tubes, which can be a pain.
What's needed is something similar to the RPG or old-style bazooka, where you have a reloadable launcher with separately-carried packs of rockets, like a 3-pack in a resealable light container that can be attached to your ALICE gear. It also needs to be cheap enough that troops can actually get to fire a couple of dozen rounds in training to get comfortable with it.
The RPG isn't really an anti-tank round and that's what our researchers are trying to devise...and individual anti-tank weapon. They've probably got it in some future form of the Javelin (fire/forget, lethal, deployable for short distances by one soldier.)
But the RPG is, as you say, a reusable, rocket-propelled, high lethality weapon that's cheap enough to put into the hands of individuals.
It's no wonder that our troops like our own grenade launcher.