If an ADC out of position should be bursted down by an Assassin
Then shouldn't an ADC not out of position not be bursted down by an Assassin?
Then shouldn't an ADC not out of position not be bursted down by an Assassin?
It's not that easy to say that
In my opinion, the game is currently balanced by -An assassin can kill most ADC's 1v1 or out of positions. -But in a team fight, the ADC is not only hard to reach, but extremely protect due to itemization and other champions.

gives the adc the burst
gives them more dmg and free get removal of CC
dmg reduction and more dmg
Other itemization
Gives them the survive-ability in team fights.
You also have lifesteal which gives them the chance to come back even if you managed to take them to 1%.
It's all good but my biggest issue is that Riot is fixated on creating counter plan to champions. Look at Mao, Zac, Darius, Galio,..etc that have been reworked.. They all have telegraphed ability that it's not impossible to dodge out of certain abilities. ADC had the luxury of having most of their damage on AA. It's why you see people saying oh a Kog beat my in 1v1 as Zed. It's most likely that the Zed missed a Q or 2 and got killed for it. A kog can't miss his AA but a Zed can miss his entire combo.
Other moba games have introduced a way to reduce the defectiveness of AA attacks because they are always guaranteed. Just like spell shield, there is shield block. or whatever you wanna call it. Not to mention, most MOBA's are pushing so supports aren't there to benefit ADC's the most. Itemization or abilities that help AP champions or tanks. Right now, support itemization is almost all for ADC or benefits ADC a lot more. ADC itemization is also balanced to make them survive and do dmg...