at this stage of the game for pve, higher lvls right now basically require aoe in build or great synergy with aoe support. running shot as the main tool in the build essentially requires people to build for aoe outside of it if they aren’t into just solo bossing, rushing, etc as running shot’s synergy with aoe support is linker. cryo and swash gathering, along with falconer circling, don’t do anything for auto attacks to become aoe as it stands atm.
the main reason why its not too strong at rank 6-7: it is auto attack, it scales very linearly and not by huge amounts. while it is mobile as much as other mobile builds, auto attack damage scales reversely with enemy stats moreso than skills do. mob HP and defense scales more than crit resist paired with weapon equips scaling less than higher rank skills base damage and multihit count. at lvl 170, you use a higher enhanced grand cross (except on flying mobs), and keeping this same weapon since lvl 40 makes scaling low. also, when lvl 200 hits most if not all mobs as you go further on have greatly increased hp that you see from time to time prior to lvl 200. these 2 points are where other builds start getting too much advantage over qs3 in situation details.
at this point wugushi hits its full potential, which is the other fully mobile build, and scales more thanks to attributes and free weapon choices. fletcher gains magic arrow 5/6 putting it just ahead of you against stationary targets. lvl 220 item didelGC is obtainable at lvl 240, this is where qs3 catches back up a bit because the major increase over grand cross, along with a r7 class. but, fletcher maxes out the best 1target damage skill in the game, and does other stuff during it too. and wugushi is already 1-2 class ranks further essentially copying your r6-7 choices, but can choose ranks for 1target if it wants whereas you need aoe big time.
so, ranks 6-7: wugushi is your rival, with attribute advantage by a bit; fletcher destroys you vs stationary targets; other builds have potentially many more ranks chosen for aoe damage. qs3 is strong but not too strong.
later content that gets added on, there most likely won’t be an xbow like GC/didelGC. however, by that time builds should be gaining enough that running shot is used as filler (and fantastic for filler at that). the loss in 80% damage buff hurts a bit, but no one should care that much about losing some duration on the buff with a different weapon. on the other hand weapon swapping still will exist and later weapons may not be large enough increase to replace didelGC for at least a while.