Which is the hardest role? Top? Lets talk about it :D
So the number one easiest role TOP
Its honestly NOT that hard to go top. Your champ pool is usually extremely tanky bruisers or powerful fighters which can make you a target, but as long as you 1) keep decent map awareness, 2) keep wards up, and 3) don't push your lane as hard as possible. Then you should always be safe,
Lets talk about the other roles.
MID LANE: is probably the second easiest. Its made more difficult simply due to having multiple directions to be ganked, and usually the mid champ pool is a lot scquisher but with more mobility usually/CC to get back to tower if needed
Then there is SUPPORT: A good support actually has a really hard job, they have to keep their laner alive whether they're good or not, they have to farm at the right times, peel at the right times, engage at the perfect times to get a good gank in. AND USUALLY in almost all of my games as an ADC main, bot will get at least two or three 4+man ganks. Then a support has to build correctly to support the entire team and their laner after the laning phase
ADC/Jungle are tied for hardest role for specific reasons. ADC's are like top laners without the toughness. Especially with the new AD heavy meta, adc's are the first target in team fights, They die easy and any assassin that is fed is almost always going to dive on them. ADC's have to pay extra extra attention to positioning and when to stay back and fight whats close or when to try and poke the back line. Anytime i've ever been 2 kills ahead of the other ADC, I instantly receive a camped lane. With 4+man ganks until towers gone. Ask myself or any of my friends, bot lane is the battle grounds for most matches. (in low elo) in higher elo's it changes because players play smarter. ADC's have it tough early game to mid game until they're full built.
Junglers have it really tough because they control most of the early to mid game play. They choose which lanes to gank, which to defend while someone recalls, which to pressure/camp, all the while trying to farm as fast as possible to keep up on level and farm. The champ pool for jungles is a little easier because they're some options that make easier for a Jg'er to make mistakes and get away with it. Which is why ADC and jungler are tied. Not to mention everyone, and I mean EVERYONE is bugging Jglers to help them out. Losing lanes or just lanes in general will beg for help and will blame the jg'er (in low elos usually) for the losing lane.
I feel like this is pretty accurate but let me know what you think :D
I have died once, a few times even twice (contesting scuttle, enemy team helps my team doesn't, no followup on a gank etc.) and still am able to farm up and be very relevant mid-late game.
and maybe a few others.


etc. They will dive your ADC, and flash away before you can even blink.
mid, and
If Ahri makes a mistake, she can ult away easily, or she can charm and get away, OR she can Q and speed boost away. Yes Ahri can be just as squishy as Caitlyn but AP items like Rod of ages and zhonays can make an AP champ semi tanky with an invulnerability.