Drops in PoE are complete and utter shit.

Without crafting bench, a chance for usable rare upon identifying is around 1 in 60. By usable I mean 3 actually useful affixes on armor/jewelry, don't count on weapons for that (I spent 30 chaos and 30 alch+scour trying to craft sth better than the starting uniques, best luck was +9k dps). In fact, I kept using Purity of Elements till level 83, cause I always kept lacking one ele resist cap (which sucks in itself since MoM is one of my defense layers.)
I'm level 87 and I still haven't seen a single 5-link and the 40 fusings I've found will very likely not result in finally getting one. And a disclaimer for the elitist jerks out there: yes, I do every armor/item/weapon node I can find and have gone sideways multiple times just to reach them.
While I'm absolutely loving Endless Delve as a mechanic on its own and want more of it, the loot/itemisation aspect of it is the epitome of terrible design. There are like 300 skills to use, but if you don't get lucky, you're forced to use one of the few Officially Endorsed Viable Skills in order to progress, which is basically like 30 gems out of 300. And you waste so much goddamn time identifying all these crappy items, always hoping (because you have to) that something good will finally drop.
Same goes for weapons, top players are still running with starter uniques (22% of 15k characters have shield equipped, 40% for HC), which is just crazy if you think about it. After 30h+ of playtime and long past reaching endgame, you are still using the same item you used at level 1. I can't even imagine the mental horrors melee starters go through.
And while it's a great opportunity to use less common but easily accessible defensive options such as Vitality or Purity of Elements, it works well only for early/mid leveling, but becomes a hindrance towards the late game, where you start needing mana for other purposes, but since you can't replace these through itemisation, you get stuck.
Imo, all in all, Endless Delve quite nicely portrays PoE problems: seemingly endless possibilities and fun, limited by terrible itemisation and gating content for the sake of it. Soglasni?