MKF are 300k xp/hr legit and around 200k xp/hr with a bot.
Pyramid plunder is 250-300k xp/hr legit. I have no experience with botting PP.
Ardougne Knights are 300k xp/hr with an aura or Gloves of Silence (they are failproof with these items and high levels). AIO thieving bots with Knights programmed can do them.
Thieving Guild has the lowest requirements to use but is the slowest. Bots can get 150-180k xp/hr, and legit players never go there because the rates are slow compared to MKF, which is the same type of procedure (just with quest requirements).
NOTE: If you do blackjacking or MKF legit, I strongly recommend getting an AutoHotKey script that has a "right click + 2 menu options down" and "right click + 3 menu options down". This way you don't have to kill your wrist by constantly right-clicking the menus to choose "Punch" and "Pickpocket." With an AHK script you can exceed 300k xp/hr at MKF, and it becomes the fastest xp available in Runescape for Thieving. Also with AHK you can simply trap an Ardougne knight and mash whatever your hotkey is with your mouse on top of the knight, which makes training a breeze. When you are 90+, this is definitely the best way to get legit experience (at the cost of being 10% slower than MKF but way easier on the attention span). Also I recommend doing Knights on a foreign world because it's less likely a person will break your knight trap. (Also, foreign worlds have less lag so that always helps.)