Where do you get loot in D3?

I really do not understand this game. I preordered D3 and played until they closed the RMAH. I was extremely disappointed to the point of anger and salt towards Blizzard with how poor the loot game was back then, but at least we could trade and make something of what little depth they gave us.

I am still wearing my original set of gear from back then, which is able to farm around Torment III in this current game state. Everything that drops now is much worse, so I can’t naturally get upgrades at all. I’ve rolled a good hundred hours of farming worth of rift shards at the vendor trying for upgrades and everything is solid red downgrades and I never get any uniques or set pieces for my preferred spec. I’ve looked everywhere and there just doesn’t seem to actually be a way to generate loot in this game and I can’t figure out why. Can please someone explain to me how to get loot in a way that doesn’t involve rolling these infuriating shards or getting carried? Can anyone give me some kind of perspective on why a Diablo game has no obvious way to gain loot?

Have you tried using the Upgrade Rare recipe in Kanai’s Cube?

It has never been easier to get items in this game. You just have to learn the mechanics of playing the game. First thing is to learn how to use the cube, next is how to enchant items: your choice of enchants is questionable, to say the least.

Also, if you have gathered so many shards, then you should also have a stack of keystones, so why aren’t you using any legendary gems?

Also, rubies in weapons are not useful once you have level 70 items. Far better to use emeralds.