If the devs ever see the time right to work on ammunition, here is an approach I'd look into. Special ammunition is actually quite nice (basically free item traits for your bow), but just a hassle to use, which is why conjured arrows/bolts win out even without providing bonuses and the special conjured ammunition make some raid weapons highly sought after.
I believe the two major reasons why random ammo is kinda bad are 1.) a stack of 100 is quickly used, and 2.) that there is so much different ammunition, that organizing them becomes needlessly complicated.
Therefore, these would be my suggestions:
1.) Increase Stack size to 1000 (conjured bolts showed how well it can work)
2.) Delete the enhancement bonus (as it shouldn't stack with the bow afaik anyway and makes a different stack between +1 Flaming Arrows and +2 Flaming Arrows)
3.) Decrease the number of possible traits (elemental damage, weak but fine, especially if they don't scale due a lack of enhancement bonus. Do we need all the banes though?), so that we find the same kind of ammo more often, which in return increases the stacks we use anyway
4.) Make several of them buyable at a vendor, so that people can just buy them
I know, there are some more pressing matters, but after selling so much ammunition over the years without even looking at them, I just wanted to share my thoughts.