Crap loot is necessary. Some unusable loot should drop and be worthless, some useless loot should drop, but be varying degrees of valuable.
They should look at adding a salvage to the Enchanter that gives you specific affix essence. This essence could be collected like crafting materials, but it would be used to upgrade a specific affix eventually to a new three tiered greater affix system. The first step would make it capped at regular maximum. The next step would bring it to 1.25 of the maximum, and the last step would bring it to the full greater affix.
This could also be used to add affixes to items that don’t have any or all the possible affix slots filled, but you’d need to upgrade them both at the blacksmith to the next tier of item with a certain material and gold cost, then you could add affixes. It would start with a maybe 50% chance of failure, but you get craftsmen experience that allows you to specialize into particular crafting, like armor smithing, bow making, weapon smithing, jewelry making, and you could further specialize into a particular slot to become a master craftsman of a particular type, or stay generalized with higher chances of failure or undesired results (but also the chance for lucky great results).
This concept would enhance the market with player made items. They could add affixes that can only be achieved through this system. Eventually, you could craft base items so you could pick the default model of your item. This gives everyone a path toward a perfect gear setup eventually, even if RNG is fighting against them, but finding good gear through RNG is still great because it saves you the time and effort of gathering materials and attempting to craft it.
If it were me, I’d set it up so a player playing a few hours per week would have no problem crafting multiple sets of useable gear in the span of a season. So, between crafting the gear and finding gear, players should be able to climb the difficulties and truly experience the experimentation aspect with builds. That’s a huge constraint for the majority of the players. They can only play around with their skill tree and paragon boards, but not so much with different combinations of affixes on their gear to see how it may perform. The best stuff in a given season is probably solved day one, but for the player that just wants to explore the game on their own without guides, this would be a really fun and engaging system.