Tanks. They have to be in frontline all the time. Oh and if the healer is bad, it will be much harder for the tank.
(Always take care of your tanks)
Well, they are still pretty hard regardless. Also I think you mean support. Specialist role was gone with the roles’ rework.
My guess is going for tank or bruiser in general, but it also depends which hero you play specifically. Mei or Johanna are usually very beginner friendly-tanks since they have great survival package, good initiation, while Ana or Zeratul are hard to play to be good. It’s actually hard to determine which role is the hardest since you have to look on the heroes as well to get the right picture.
Bruisers are only hard, because their role is usually overfilled with tasks as they are also solo laner, otherwise it’s also hero dependent.
Maybe, if you are Lili or Morales, but I wouldn’t agree for Deckard, Malf or Ana, because they also have very nice CC utility, which can be game changing and needs good timing and positioning.
If we were to take specific heroes in to account then totally. Some of the hardest heroes in the game are healers.
I think Tank is the hardest to “learn”. Actually playing them isn’t that difficult. It is just the most mis-understood role in the game.
Also, having a good Tank is kind of a force multiplier. A bad Ranged Assassin can look good behind a competent tank, and a good Ranged Assassin can get shut down behind a bad Tank.
But if everyone is playing well, Assassin is harder than Tank to actually execute and I would say the skill threshold is higher on most of the Assassins.
So yeah… Assassin is harder to play, but Tank is less understood and generally played more poorly.
Depends, it’s also hero dependent. Mage heroes like Tass are usually not really hard to play, he is rather easy to learn, hard to master. And if tank is less understood then it is harder than you might think.
A tank is an initiator and defender and this tasks are kinda contradicted, because the one role forces you to play offensive, but the other demands to protect your team. To find the center is the key here, but it’s not always easy. But your tank isn’t your sandbag !!!
From hardest to easiest:
Support~Tank>Melee Assassin>>Bruiser>Mages>Ranged AA Assassin~Healer
I’d say Supports and tank are about the same in difficulty, just a bit different skillsets you need to master but essentially both require a solid gameplay knowledge and decisionmaking skills and are thus hardest to play.
Melee assassins have to have a good eye for when to go in since their damage isn’t very high, have limited disengage options and have a low health pool.
Bruisers are separated by a wider gap from melee assassins because they have good damage to health ratio and often come with sustain options so they’re generally harder to pressure to the point they can sometimes act as tanks.
Now I had to separate ranged assassins into two categories, mages and AA. Mages are a bit skill intensive when it comes to mechanical side of things but otherwise they have little to worry about if correctly positioned.
Finally I’d say AA assassins and healers are the easiest to play. Some healers may require a bit more skill to shine but by and large I’d say they are equal in skill required to be effective.
Thing is you need a tank. You don’t NEED a support on a team.
Not true, since a support hero, except Zarya or Medivh, fills usually the role of a solo laner like bruisers I wouldn’t say you don’t need them, because it’s like saying you don’t need bruisers, because you have a tank and camps can be done by assassines as well.
An Abathur or Vikings can be very useful for the team, if you know how to use it to your advantage. Medivh works as a mage hero and Zarya is kinda like a bruiser though.
And btw Tooton I would say tanks are also not mandatory for the comp, I have experienced dual bruisers, where I won matches, because bruiser can take a bit of damage. So I could imagine dual bruiser with Uther for example could work.
So I would say you need a good frontline and it doesn’t matter, if there is a tank or not, it is comp dependent.
Looks at my 4W-16L Johanna.
(Depending on the season, in HL, I was high plat/low Diamond)
(And I am/was a flex player)
Looks like you are playing very aggressively, but if it’s working out for you, why not. 
/EDIT:
I read it wrong. Maybe you just have bad luck with your team, don’t know
I am also a flex player, but my main roles are still tanks/bruiser. I am horrible as assassine, especially melee (aside from Murky or Samuro). 
I honestly have no idea when I played those games, probably mostly in the few months after her release…
I actually wants look at the tanks I actually have played a lot to see where winrates are on them. Whenever I have a chance to sit down at my computer.
Also, I probably just had bad variance. Or maybe I just suck at playing Johanna!
Maybe. Like I suck with Diablo or Muradin, I don’t know why, probably because they are kinda dive-all in tanks and not defensive ones as Mei or Joh.
Hypercarries are hard to play because they die very quick and they need to deal huge amount of dmg and kill enemy players so they can’t just stay passive/too safe all the time. They have great responsibility and that’s why they get a lot of support (tank/heal) from their team.
I play with a group of friends and there is a big gap in skill level between some of the players. Our most successful setup is when the high ranked players are on sololaners and assassins while our lower ranked players are on tank/healer.
Our worst setup is when both high ranked players are on tank/heal.
I wish we had hypercarries
Butcher, Zeratul, Illidan. All are very hyper carry like especially The Butcher. Just babysit the baby Butcher and when he has grown up, he will melt the enemy team for you. Having access to one of the stronger heroics in the game with 20 on an assassine is insanely good.
If The Butcher would be in LoL or Dota 2, he would wreck all the carrys, except Antimage. Because Antimage would just drain his mana to 0 and the Butcher can only AA him, but he can blink away, when in danger.
Let’s not forget the best one of them all
https://media.discordapp.net/attachments/211874493726064641/803633782393405542/340.png
He’s extremely counterable
Score:
Tanks 9
Bruiser 1
Assassin 2
Stupid answers that avoided an simple question 4
Every role is easy with a good healer taking care of you
Ok let me make an argument for bruisers
Obviously answer is tank for uncoordinated play
But in coordinated play it seems to me like bruisers have it the worst. While the tank can count on healing and the assassins to follow up, the bruiser has to always watch for ganks bc they come quickly and out of nowhere. He needs to know whrn to lose xp and when to cap points. Also most of the gimmicks (sonya whirlwind, leoric w,) aren’t going to get the same value they would if it wad ranked.