The monk in my experience was not behind the curve levels 1-4. Their damage output kept up with two weapon fighters/rangers with the two weapon fighting style - which was actively ahead of great weapon wielders without GWM. It was only at level 5 that the two weapon fighters fell off. As for AC? Levels 1-4 you were looking at studded leather armour anyway.
They can keep up with the damage curve, for a few rounds, anyway. But are much squishier than other melee types and don't offer exceptional utility, so their niche is unclear. Or use their ki for patient defence to keep up with survivability, while falling off on damage.
Question: does any version of an ideal party composition from levels 1-4 currently feature a monk?
Level 5 of course they fell back because twf meant more with a greatsword or even a longsword with duelist style than with twin scimitars. But they got Stunning Fist which was OP.
I think Stunning Strike is a bit overrated; it gets spammed because monks don't have many options, and when it works it is fantastic. It typically has a low DC due to monks being MAD, so it gets resisted a lot, leading to rapid resource depletion. And it makes monks boring - one thing I am currently enjoying about playing a Way of Mercy monk is having a decent alternative use for ki, which most monk sub-classes lack.
So thus far playtest monks are gaining +1 damage to their martial arts die, improved step of the wind, and a big nerf to their signature ability, stunning strike. Like, we can debate whether this is an overall buff, nerf, or wash but I'm not seeing much here that will move monks out of being the definitive bottom echelon class, at least not in levels 1-6.
The monk's real problem was that levels 7-13 were soggy with almost no offensive scaling and no non-situational defensive scaling.
(evasion and poison immunity are both great when they are needed but you can go entire adventures with neither coming up). Level 7 is definitely not soggy, level 11 subclass abilities have been polished, and level 13's ability to return Eldritch Blasts to sender covers huge swathes of things while bonus actions to remove conditions are much better than full actions.
I don't think that level 7 is nearly as amazing as others do, but that's probably because our group is very liberal with the length of short rests (it's narrative driven) and don't often run a lot of back-to-back encounters. But what actually improves for monks during these levels? As the base class you can get di back with a much shorter rest, once and...what else? Self Restoration is basically a nerf, and everything else is a wash. You do get a better sub-class feature at level 11, all of which have to do with mobility.
So...play a monk so that by level 11 you can live the dream of being the fast skirmishing warrior that WotC are clearly telegraphing as the class fantasy? They also tell us that 96% of campaigns end by level 10...
I've not seen anyone pick up on the stealth nerf to Stunning Fist that with better feats you're less likely to pump wis (and 17/14/14 is going to be the default starting stats for most although 16/16/13 is still possible).
Nor have I seen anyone pick up on the stealth buff to survivability from the Sap property; sap is a mediocre choice for fighters because in a duel if you hit someone with a sap weapon a second time it does nothing. For a monk once you've hit someone with your mace you switch to unarmed attacks for more damage.
I see weapon mastery abilities as a wash, since every martial class is getting them. If anything, they are overall a nerf to monks, since monk unarmed attacks won't get to use them.
