There is one thing that is the boon and the bane of tanking in this Game.
A boon for every Player who just plays them for faster Queues or are super new into tanking and a bane for every Tankplayer who goes for higher Difficulties.
Tanks are literally just blue Icon DPS Classes, with more bulk but the same mastery.
If we take a look at their Kits, they are focused around Damage and Damage Mitigation is just a Minor aspect covered by some OffCD Skills.
Keeping the Aggro is just a small side Task, often covered by Tanks using a single Aggro Combo at the Start of the Fight, before dropping into blue DPS Mode.
Their Specials are not focused around Damage Mitigation and Aggro Management, they are high Pot Specials, like Fell Cleave or Bloodspiller.
And now even the Spam of those Classes sells this. We spam Skills like Dark Arts and Fell Cleave. Skills that just have a higher Pot and nothing else.
The whole mastery of those Classes is to raise the DPS output after a Player memorizes the Basic Features of a Fight.
Some Raids even come with DPS Checks for Tanks, which again cements their Picture as blue DPS Classes.
And here comes something that might pop up in the Head of some DPS Players looking at Tanks.
"If tanking evolves so much around doing high DPS Numbers as the mastery, why should I not instead just play a DPS Class like Dragoon or Samurai?".
Stormblood even confirmed this Picture with 5.0, when the DPSfor the DPS Jobs made a huge jump and the Tanks felt weak because of small Numbers.
Especially with Kits, that sell Pot Numbers and some minor Effects of certain Attacks.
In the end one Class is fighting a blind but bulky Monkey and the other one fights a blind Money, that sometimes hits them.
And while this sounds super obvious to everybody, it seems often not so obvious for Game Devs.
Is there a MMO out there, who did this really really well?
I would love to see the Gameplay of that, because till today, I never saw a MMO doing this really well.
Would a real difference between those two Combat Roles make more Player play Tank?
Maybe...maybe not. Nobody really knows, but maybe it could make this Classes more interessting for Players who are interessted into tanking but after Leveling all of them move back to their DPS Class.
Maybe it would raise the Numbers of full time Tanks and reduce the Number of Part Time Tanks in the Game...maybe...maybe not, nobody knows for sure.