Only in that literally any class benefits from better defenses.
But, again, that is my point. All those defenses don't define the monk playstyle into being a mage slayer, because if you put them on any other class, that class doesn't actually change their combat style.
Note that barbarians are a frontline damage role, not a tank role. Their high HP offsets that their damage method involves wading onto combat making themselves vulnerable.
Barbarians are the worse damage dealers of the three major melee classes long term. Run the numbers without GWM w/Reckless attack, and the barbarian consistently falls behind. And now GWM doesn't do what it used to.
Greatsword, level 11
Barbarian: 4d6+8+6 = 28
Fighter: 6d6+12 = 33
Paladin: 4d6+2d8+8 = 31
And note, this is the barbarian using their resources, while the fighter and the Paladin are not using ANY resources. It is better at level 5, but not by a lot, and only because we are not accounting for any other resources.
Barbarian: 4d6+8+4 = 26
Fighter: 4d6+8 = 22
Paladin: 4d6+8 = 22
Now, depending on your subclass, the barbarian CAN get really good damage.. but not all of the subclasses do that. On the flip side, there is maybe only a single subclass between all the fighters and all the paladins that is as hard to kill as the Barbarian regardless of subclass. Okay, two. (Champion for regen, Eldritch Knight for Shield)
The suite of abilities monks have is what WotC typically uses for assassin classes like rogues which are expected to be fairly weak to direct physical confrontations with frontline fighters and tanks, but good at ignoring the attacks of their squishier targets.
But this is exactly the problem. Monks are a melee class. You can't get around that. Rogues CAN go into melee, but they ultimately never go into melee by themselves. Sneak attack incentivizes you to hit the same target as your own melee group. Only a rogue attempting to one-shot an enemy will ever attempt to attack from hiding on a solo target.
Rogues actually aren't assassins, they are almost combat support, because their typical move is to hit the guy being hit by their allies. Additionally, rogues are much more reliably mobile, and have much better ways to avoid being targeted at all. AND they can swap between melee and range without a drop in offense whatsoever.
Meanwhile, the plan proposed for monks is to dash behind enemy lines solo, and hit enemies that can't hit back. A monk going to hit a melee frontline enemy is in trouble ALL the time. But they are a melee class, and they lose out on a lot if they switch to range.
Moreover, ignoring roles, they have these defenses instead of higher hit points. In Team Fortress 2 terms, they are scouts who bounce around bonking snipers and medics to death after simply jumping over the heavy. They may need to be better at their role, or their role might not be valid in 5E and they need to be scrapped, but their suite of abilities is not subtle.
I think it can be agreed that, as designed, the Monk fails in their role. But I also don't think that the monk's role should be so... limited.
We always talk about the monk going and hitting squishy ranged targets, but let us compare again to the Rogue. Who is the rogue best at damaging? Everyone. If you have a ranged rogue, who has hidden themselves to get advantage, or even just uses steady aim, they can hit and deal sneak attack damage to any target on the field. Heavies? Rogues can handle them within their playstyle. Mages? Same. Artillery? Same.
But, the rogue in melee's playstyle is fundamentally to work as a team. The rogue goes in to an enemy already engaged, and hits them. That's why the rogue, with their no limit disengage, is so much more effective in melee than the monk. Because they are never trying to be a solo act. Solo rogues are almost always ranged, and rely on the frontline to keep the enemy away from them, while they hide and use cover to protect themselves against ranged retribution.
And I think this is why I want to move the monk, just a little, to be more capable as a frontliner. Because the monk is always assumed as a solo act, they don't have abilities that require teamwork like sneak attack does. And unless you have double the movement speed of your enemy, and your enemy chases you, you cannot kite in melee. It simply doesn't work. And since not every fight is going to have a a glowing weak point enemy for the monk to safely engage in melee, they need some way to deal with frontliners effectively. If they go to range, it ruins the concept of the monk. So they need to be able to stand on their own two feet here.