Look at it this way, The game is based entirely around RNG. So far the main thing I have noticed is that when botting certain profiles(especially Ghom/Kulle) you can usually find yourself on what appears to be a FIXED loot table. Meaning you can see the very same items over and over again very common, and rarely if ever, see a desired item that isn't trash. But it feels like every few days to a week perhaps this changes, and the loot with it. One instance would be I have been running Ghom on T4-T5 for 4weeks+ now, The first week and a half or so I constantly saw the same items over and over, Pig Stickers, Crushbanes, Blackthornes(these drop for everyone it appears regardless) Sever, Skysplitter, Maximus, All the common weapon/armor(aquila curiass, goldskin, heart of iron etc) chantodos/mykens nonstop on my wizard. Finally one day after nearly 2 weeks of botting, All of a sudden I started seeing new items drop. And I knew they were new for sure because of the fact I would see the 'new transmog' message occasionally while watching the bot. Soon as this period switched, after a dry spell and being paragon 400+(started botting at 95) I finally saw a tal rasha belt, then a helm, then a thunderfury my very first one, then a shard of hate(same day) then I had not 3, but FIVE mirrorballs drop in the same day. 3 were almost back to back drops and came on the same book of cain ID. 2 +1s and a +2, The final one I found was another +2. I also found 3 more moonlight wards, and various other items up until that point I had NOT SEEN in over 1000+ legendary drops from botting.
Now I am well over Paragon 550+, I have about 2.1b gold and I try to spend as much as I can whenever whether its on gems or not caring when something I reroll gets to be 3-4m+ per reroll because well its gold and a few mil makes zero difference. I am almost out of certain gems like topaz due to having 2 wizards and 1 WD both of which have 280int gems etc. You could always just switch it up and try manual play, do some rifts or something. I don't always bot lately now that I use multiple accounts botting(sometimes follow sometimes not) but I enjoy putting the items the bot finds to use. Just give it time imo, I have seen plenty of people find everything they want within a few days of botting, even manual play. It just comes down to RNG luck and imo if your on the right loot table for whatever period. My buddy who didn't bot managed to find 3 thunderfury, +2 mirrorball, shard of hate, full tal set, various other items that were best in slot rolls all within the first week of RoS release. I watched him go to HC only to find another tfury at level 43 before I still had not found one. He ended up getting his +2 Mirrorball on his HC wizard the same time I got mine on SC. Sometimes RNG just shits on you, So far my WD has been up and running barely 3 days and he has found a SMK/mask of Jeram/2pc jade etc.