Example: Rengar is built with one damage item and then goes off tank. Thoughts? what even is an assassin in this game? Oriana does more burst damage than most assassin with items and is very safe.
orianna doesn't do more burst damage than an assassin unless you've fed her. And even "support" Sona is going to do more damage if fed and building AP Items like
and
than an assassin who is behind .
Someone that goes in, bursts someone down, then gets back out with mobility. 
It's because going full damage and having no cc is harder to succeed with unless you are incredibly overturned. it's easy for riot to keep nerfing assassins out of play because they arent popular unless they are broken and well if broken you can just nerf it anyway. At a certain point the constant nerfs just make it so you cant function as a damage dealer because if your combo can't 100-0 an adc in a 1v1 you arent gonna do a damn thing once the support drops a 400+ shield on them while you also are exhausted then redemptions gonna hit making your job impossible. This isnt even adding the melee range and lack of cc in most cases.
To put this in perspective, you need 3800 for 
, 3100 for 
and 2900 for 
that's a combined 9800 Gold. to be able to start to 1 shot people. If you're talon, or zed to kill and ADC you just need lvls. And if you've ever played a normal game of league you don't need to me tell you how quickly a zed or talon with little to no items can delete a squish adc bot lane one he hits 6. If you can't snowball before you opponent can get 10k in gold worth of items, then you need to improve on your assassin skills, cause Orianna is meant to played for later on in the mid game and will do damage once she get items. Before that she's easily abused if you play right using an assassin and either killing her or if she's taken barrier/exhaust, you roam and get ahead. If you want to play for the late game ... play a control mage DESIGNED for mid-late game.
