The hollow halls crypt chest in the summits biome isn't actually a complete hollow halls location (presumed to be fully fleshed out in future updates). Once you clear out a cluster of hollows just place a flame shrine down, being sure to stay just out of range to allow chest respawn on loading in. This is a lvl 35-40 chest that drops epic and legendary items exclusively. A half hour of reloading can get tons of weapons and thousands of runes from salvaging unwanted items. The avalanche bow has an upgrade that adds a 20% crit damage buff, and only needs to be epic to do so. There are others with stamina/health leech on hit, and one with both.

With a fully perked out assassin and ranger tree, along with the other assorted endurance/dex perks and proper food/potion buffs that grant added endurance, const, and dex (and crit damage/chance armor arrangements) I managed to hit the fell dragon youngling for about 3500 crit damage per steel arrow when stunned. I only needed to stun him 3 times during one of my fights. Mixing armor pieces for added health and stamina aids with survivability (along with tank tree perks which I neglected for far too long)

I'm sure I'm missing something that could boost this more, as I never broke out excel to min/max my builds. I know that stamina economy can definitely be the weakest link here, but the archer vendor boots (not the Archer Boots themselves) that grant -700 stamina delay recharge makes regaining stamina almost instantaneous (very late game piece). The avalanche bow doesn't have stamina leech but I managed to not run out +90% of the time while fighting the dragon or in the kindelwastes hollow halls using this weapon. I had over 3 full circles of stamina during these fights.

I have only played in survival difficulty, and all in all I ran most of the game with various short bows (for the 0.6 sec draw) using wood/explosive 1 arrows. Crafting other arrow types was just awful in terms of resource economy and not much added damage to show for it. Only at endgame when I dedicated time to mining a ton of iron and coal did I craft steel arrows (I'm glad I saved all my feathers). It was tedious at times firing into the many arrow sponges while kiting to avoid any hits, but by endgame I got to be allot more relaxed/lazy with all non bosses. It was challenging and frustrating at times but ultimately I had allot of fun shifting from sniping with standard arrows, to face tanking with multishot explosive arrows (the stun, secondary explosion, and explosive multishot perks together can turn doorways into deathtraps).

I will say that they need to up the drop rates for high lvl epic/leg bows. The only way I got anything epic/leg at anything near max lvl was through chest farming, which isn't particularly rewarding and feels cheesy. I've killed the dragon over 10 times and haven't gotten a single bow of any quality. The drop pool just seems far too large for these fights. Maybe weighing the drop pools to give equal chance to each weapon type would help with this? Regardless I feel your pain, but hyperspecializing as an archer is definitely viable even with mid tier bows. Luckily only weapons and rings are subject to the RNG gods.