It all boils down to this.
Monks sucks because their resource, Ki, is not plentiful enough. So they can't do their shenanigans all the time.
For me this is what makes the monk an attractive class.
1) The monk needs to manage his resource carefully. Agreed.
This is perhaps, the strongest point against and for the monk. The monk is just like the rogue, and not the fighter. A rogue that is unable to sneak attack is even worst than the monk. Yet, no one brings that up because a rogue can manage not to get into that situation with relative ease by moving close to an ally, using disengage as bonus action, hiding, etc... The monk, when left with no ki, is left with two attacks. If the monk is forced to stay at a distance, this means that the monk will be stuck with 1d6 +dex for each possible attacks. At high level this implies that a rogue will potentially make 1d6 +dex with a small bow once, but he will be able to possibly add its sneak attack damage, 10d6. A better comparison would be with a paladin or ranger or barb that no longer have any resource. They are stuck with their two attacks too. Yet, no one bring that up. Strangely, it does happen a lot in my games.
2) The monk relies on short rests, which can be DM dependent. Agreed.
This is both a strength and a weakness. With an assumed two short rest per day (average 2.5 for convenience) the monk will still get low (or depleted) on Ki. But the monk will be able to "nova" if needed be about once out of three fights. Not all fights should be deadly and not all fights should warrant the use of Ki. Monks sucks when they are deprived of short rests and all fights are on the "deadly" range. For me, this is more of DM lack of understanding and pacing when faced with such short rest dependent classes. But monks are not the only one that are actually punished very hard when their resource (Ki) is depleted. As stated before, a paladin, ranger, barbs, when out of resources, are no longer able to do a lot of damage either. With no magical weapons, these classes are stuck with weapon + stat bonus damage and only one or two attacks. Some will have a better AC, other will be about the same. When the 5mwd is allowed, these classes do not need to manage resources. But when the 6-8 encounters are enforced, they are in the same predicament as the monk. The only advantage is that their weapon might do better damage than the monk hand to hand. Then the monk should use a weapon to "up" its damage. A quarter staff is a great way to enhanced the monk's damage. If the quarterstaff is magical, the better. People often forget that the monk can use some weapons, including bows and throwing weapon to exactly the same damage potential as a paladin, barb or ranger.
3) Almost no magical suits the monk to help them. Agreed and not...
There are some that will help. Glove of Ogre strength are great on a monk. A +4 to athletics means that the monk will be better at grappeling enemies. And this item is often unneeded by strength type characters as they will raise their ST to 20 anyways...
A ring, bracer or a cloack of protection will help the monk just as it will help any other classes.
A potion of growth is even better on a monk. +1d4 damage is great, especially with flurry. Some DM might argue that you need a weapon. A quarter staff is still a weapon. The monk's fists are weapons for all intent and purpose. If you consider the monk to be weak, then you should allow this.
A magical short bow, quarter staff, throwing weapon (with the return property) that the monk can use is also a boon. A distance weapon can be quite useful.
And now, the surprise items.
Animated shield. Yes a monk can't use a shield. But he can wear this one, utter the command word and benefit from the protection just like any other character. He can't wield a shield and benefit from its martial art, but the shield is not in use, only it's special ability.
Dimensionnal shackles. The monk, with stunning strike can put these shackles on an enemy in no time.
Glove of missile snaring. Yes the monk can already do that. But doing it twice is even better.
Robe of scintillating colors. These are not restricted to mages and they do not count as armor. It is a free Patient Defense 3x day + a possible stun to all within 30 feet. Since the monk moves a lot more than that. It can mean failed saving throws on a fireball for a lot of enemies. And the monk with evasion will certainly save taking no damage.
The robe of stars, even though less usefull that the preceding robes, are still great on a monk.
The ultimate staff for a monk is of course the Staff of Striking.
A lot of people forget that some wands are usable by all and not only spell casters. This is a big change as a monk can use some of these to great effects.
Winged boots. These will give the monk the best flying speed ever...