But I think you're wrong about the path that restrictions would take in the US: the slowly boiling a frog approach won't accomplish the goal, anything too quick, sharp and raw will merely spark the 2nd American Civil War during which "gun violence" will go way up. And most any restriction scheme will increase gun violence, if only on the part of the authorities using force to seize guns and the like.
Maybe in the long term public attitudes could be changed, the 2nd Amendment repealed, and the path you envision might happen, but that's the work of generations and will require a reversal of the renorming of gun ownership we've seen in the last quarter century (I take Florida's 1987 establishment of a shall issue concealed carry license regime as the start; today 42 states have them, de facto or de jure).