Personally I'd like for it to rain legendaries. Say you want to go for a fire build and want to do as much fire damage boosting as possible. Fairly easily you can get your bracers and amulets set up, and then what? You wait for that lucky drop. Are you even going to be interested when you finally get that drop, maybe you'll be onto something else. I don't think getting items in and of itself is an endgame. I'd like to try out a bunch of builds, play with a large varieties of legendary affixes because I think they'd be fun to use, not fun to get. Playing with my usual most effective set up is going to get boring a lot sooner than having wide variety of stuff to toy around with. You've got these items and mechanics that can keep things fresh for people and they're locked behind absurd RNG.
At the very least there should be loot tables on monsters or different kinds of rifts that drop a certain type of item. Something to target the grind that we're on, gambling is a smalls step but I want it to go deeper. No I'm not going to quit the game once I've completed my class set or whatever, it's not like Blizz are trying to squeeze a subscription out of me. I mean, come on.
The game is still fun but seriously. And take out those trash legendaries that only roll 100 higher vit/dex/str/int.