I used the search button about the word random, however could not find anything like this. If not already discussed, here are my 5 cents (of an experienced player 20+ years ooO)
Driving force in D3 and similar ARPG is explore to find the perfect stats on a loot.
I suggest rarity system (green,blue,purple, orange, yellow = unique) this is already the meta for most MMOs.
I love that random mob groups spawn nearby and have random drop.
Make me explore (expedition like) and kill quest monsters, or RARE monsters, or mine for RNG “cubes” which could be armour, weapon, material … etc. The key words are rarity and random.
Apologies if this is already discussed without the word “random” in other threads, which is why I could not find it.