I never really understood how aftershock would work on ranged characters lux or whatnot

If u take aftershock on a ranged champ but aftershock burst procs on melee range what even is the point? the defensive stats don't even last that long on ranged characters to be worth it, i thought aftershock made engagers job easier so they don't completely melt when they go in, how does it even work on lux? lux is always attacking from a safe distance does she even need it

to me taking aftershock on a ranged defeats the purpose of aftershok but somehow it's considered op