There is nothing wrong with MMOs using Taunt. It is a perfecly resonable solution to practical limitations of the game engine.
Taunting / Intimidating and so on was a very common technique IRL. People/creatures are not dead wood.
NOTE the very very limited
but still available stopping up a doorway just quit being the only way which it was previously. When it's all you got it gets glorified.
The problem comes when you import it back into PnP, and hence simplify the far more sophisticated tactics the medium allows.
"sophisticated" -stop up a doorway is sophisticated? It was a desperate only way for decades LOL
The Cavalier cannot interfere with an adjacent a wizard casting all hail wizard superiority we could do so in an absolute way in 1e but the specialist defender Cavalier cannot in 5e because>>>?????? .
You have some of the same mechanisms or similar in 5e and may be some hard to find distributed around 5e made it less tied to a class. (yes I like that)
4e defenders also didnt do it ALL the same way the fighters defending had much different methods way more punishment than the Aegis swordmage for instance.
Even within the same class it was not the same way some didnt have the risky opening themselves up trick... some didnt have the rake by a bunch of enemies and draw all their attentions trick (different method of applying the condition)
The Aegis swordmages shielding which was different than the Berserkers Later they introduced an aura mechanic which was different than straight up marking but also limited. It was nice for being a better door stopper by the way.
While it was closer tied to specialists in 4e other characters like a Warlord could up their armor class and toughness and definitely do defender As pointed out reducing your defenses via maneuvers and choices was also an element on the table in 4e. Warlords doing that trick actually did more than make themselves tempting they opening up the retaliation for their allies to do.
Having tricks to swap places with allies to defend them and take the hit was a Paladin thing (not sure if others had something like it).
There are tricks for lending ones shield in 4e too they are sometimes from feats sometimes powers (you may not have them) -
And so on and so forth...
You are taking ONE part of the picture and ignoring the rest. Your analysis is flawed and narrow. (mine of 5e has some of that going on but its getting better). The idea there is/was "one way" to defend is just off base (even if specialists had a common element)
Marking is more subtle in 4e because advantage/disadvantage was; It very much needed the supplemental effects and those created many distinctions. Many of which really didnt work against ranged adversaries. (Fighters could mark an enemy a long ways away but it is minor distraction where as a wordmages it was fairly near, however swordmages could maintain the mark and run/maybe teleport no matter how far away and still get nice triggered effects).