Ok, let's get one thing straight. Playing tank is boring because you only press 2 buttons as a tank.
Point 1. If you only press 2 buttons as a tank (or skills) then you are definitely doing something wrong and then it's no wonder that you don't hold aggro.
Point 2. What do rouges, scouts, champions, mages do. Do you feel the presses more? If you think that you are hopelessly lost and you should see how many skills really change and that usually only a few elite skills are added (depends on the class) - I'll fade out that almost every DD with Kitty, Lua or anyway similar plays.
Point 3. If we compare. Players with gold gear and end-game stats, then we shouldn't compare that to a new tank player who might not even have all set skills, etc.
Yes, tank classes have been the same for a long time. But as your guild member wrote, you can also refuel with other classes. (If you like that, gladly, not me - but that's just my opinion)
Why weren't they changed? Quite simply because it is simply not necessary. You can easily keep the aggro, apart from the fact that the mobs fall over within seconds anyway and you don't actually need a tank.
On the topic of the new player leaving the game because they can't keep up or can't get into the game. I wouldn't say that it's because of balancing. I think it's more because of the toxic community that screams at every little mistake someone makes. For example in Rofl. (I definitely count myself among them)
Nevertheless, you can stand up and if these players are in a guild or just have questions - after all, it is an MMORPG where the basic framework should be communication - then you can help these players and explain what they are doing wrong. Many players come and just adapt first. Play leech classes (I don't think need to enumerate). How should new players who mostly have nothing yet, find connection to players who are already finished and just wait for something new to come.
I can understand that you would like to have variations in the tank class and maybe not just play with the same rota all the time or sub class. But then, make suggestions and don't argue the class is boring because xxx.
But I would like to change skill x, y so that he maybe does that (for example, disarming).
Because in the end, only a few buttons are pressed on each class.
~ just my opinion!
Greetings