The ADC Problem: Why ADCs aren't the actual problem.
Now, before you downvote, hear me out.
The problem isn't ADCs being OP or ADC itemization being obscenely good. (Yeah, some ADC items are broken but that's not the point). Rather, ADCs are being picked left-and-right in all lanes because their specialization, item diversity and sheer choices are through the roof and more in line with where Riot wants to take league.
To further understand this, we have to go back to the ADC itemization/Mass ADC update. Now, yes, there are champions who are better and were broken on launch, but the real thing this did was give ADCs powerful niches and items to compensate for any shortcoming or to enhance their own abilities. As a quick example, let's say I'm playing Caitlyn.
What do I have that I can buy in terms of how I customize my way-of-play?
to increase my raw damage output.
to increase my ability strength.
to give me stronger sieging poke.
to benefit my dueling potential.
to deal with high HP and high armor units.
You get the idea. I have tons of options to edit and customize my playstyle. While there are some items that are better for some champions, one cannot deny that most, if not all, of these items have some level of usefulness.
Now, let's say I'm playing Malzahar. What options do I have?
for raw power.
for power and health.
for high HP (Although it doesn't work great and only excels when paired with rylais)
for power and defense.
I could go on but I think the point is clear. If it isn't: When I play an AP character, my options are far more limited in scope. Customizing build usually only gives me one path. If I want to burn high HP targets, I generally have to grab Rylais AND Liandries when an ADC only need Dominiks. If I want ability spam, I generally need to invest 2-3 items in just CDR when an ADC can get that much through one item and maybe boots/runes. etc etc etc.
Now, you'll likely go "Wow so unfair nerf ADC items" but hold the horses. This is where Riot WANTS the game to go. In a perfect world, every class would have itemization options like ADCs and every tank, fighter, mage and support would have the clearest cut of roles. Are ADCs a problem? Yes, because you're comparing a 2016 product to a 2013 product. Even the small item changes Riot does make to other roles, while good on paper, don't mend the problem as they should.
I'm not going to try and defend Riot's speed on implementing these changes. If anything, a speed like this will leave some classes far too much in the dust to justify what they actually need right now. However, I will say that complaining about ADCs right now isn't really the issue. You may disagree with me but what I think is that we need to bring OTHER classes to the level ADCs have, not blindly nerf ADCs so that they fall in line with the old and outdated products.
with
you are already predefined as a burst assassin not a tanky dps because of her kit. And so
doesn't make any sense.

Ridiculous mixed damage and a buffed rumble ult on his passive.
"Ezreal is abusing IBG, better nerf his ult cd" - Riot
Ridiculous damage while being stupidly tanky.
Toxic mobility
The game has an attack speed cap for a reason, but riot seems to have forgotten that.
Blatantly overpowered ult even without a base damage. Make it rain is a guaranteed thunderlords proc, this has more to do with thunderlords and not mf, but still.
A lot of problems adding up to make her a big problem, her blind is bullshit.
%Max hp true damage is an extremely toxic mechanic that doesn't belong in the game.
Was built just about every game and you only substituted if
if you were Corki or Ezreal. But ultimately that is what 90% of all adc builds looked like for years. The only time you could afford to get something different like
or Zephyr was if you were stomping.
or
.

,
, 
For a bit more damage
for if you need some armor pen but no one has a spectactular amount of health
if AP is cc'ing your ass to death
if you are a mage that can make use of shields/ healing, such as orianna and you have an attack speed reliant team.
If you use a lot of mana, want a lot of AP, and want a shield for their burst and more survivabilty (kinda like a better steraks)
If you want a slow, more surviability, and are an auto weaving mage like TF, kassadin, Lux, diana, etc.
If you really want to fuck up that one person's day.
In case you need more sustain.
and