I will be talking about Glaive frames and Melee verbs (or the lack thereof).
A quick reminder: Glaives were first introduced with the Witch Queen expansion, and first given access to benefits provided by Exotics in [url=https://www.bungie.net/7/en/News/article/destiny2_update_630]season 19[/url]. Season 19 is the last season to take place before the Lightfall expansion. At the time of writing, it is season 20, the first season of Lightfall.
Currently, there are 6 Legendary Glaives and 5 Exotic Glaives. The 6 Legendary Glaives share a grand total of 2 frames, Adaptive and Aggressive, and will be a focal point for this discussion.
The Adaptive frame,
"Hybrid melee/ranged polearm with a frontal shield.
Generates energy on dealing ranged damage."
This frame itself is essentially perfect when singled out, as there is nothing to compare its performance to. The problem arises when you introduce the Aggressive frame,
"Hard-hitting, slow melee/ranged polearm with a frontal shield.
Generates energy on dealing ranged damage."
This frame, coupled with the existence of the Adaptive frame, creates a few problems:
[u]First[/u], both frames hit for the same melee damage. The Glaive melee is directly specified as "Hard-hitting" within the Aggressive frame’s description, yet there is no difference seen within the frames themselves.
[u]Second[/u], both frames perform melee attacks at the same rate. This is yet-again inconsistent with the aggressive frame's description; Specifically, "...slow melee/ranged...".
Although this may not be seen as a problem until the [u]First[/u] issue is solved, it should still be considered an issue in the event of the [u]First[/u] issue being patched, or until the Aggressive frame description is updated.
At the current moment, with both the speed and damage being equal, an argument can be made in favor of an updated description instead of an update to the Glaive melee itself. Though I would not take this route, as it limits the Glaive's overall potential while buildcrafting and is not healthy for the weapon archetype.
Example, the only factor I look at in choosing a glaive is the perk pool. With the frame meaning next to nothing at the moment there isn't much else to concern myself with.
I will now move on to melee verbs, or the lack thereof.
The problem is that glaives are required to be constantly tested for functionality when buildcrafting. Melee verbs aren't a necessity, but can help determine what works and what doesn't.
Bungie stated in season 16's [url=https://www.bungie.net/en/Explore/Detail/News/51250]TWAB[/url] (slated for season 17), that "a Glaive melee is a basic melee attack", "should benefit from melee damage buffs (such as Winter's Guile or Wormgod Caress)", and "should not activate perks that trigger off powered melee damage or kills." With this information we can define glaives to be kin to, if not the same as, an uncharged melee.
This is not as intuitive as you may think as much of Destiny 2 defines melee attacks as simply "Melee". There are some exceptions, Heavy Handed for example requires a "powered melee final blow" to proc its effect. In this situation, it makes plenty of sense as to why a glaive melee final blow is unable to activate Heavy Handed. As previously stated, Glaives should be equivalent to a basic melee attack. However, if we look at Focusing Strike, no more than 2 slots away from Heavy Handed, it requires "damage with a melee attack" yet is unable to be activated by using a Glaive's melee attack BUT can be activated by an uncharged melee from a Guardian.
I'm not necessarily arguing for the inclusion of Focusing Strike, but in this case a better distinction between a Glaive melee attack and the melee attack described by Focusing Strike.
Another example of this is seen when using the Titan Aspect Offensive Bulwark. Offensive Bulwark can be activated and used with an uncharged melee, granting the user "melee range and damage". As we know by now, melee range cannot be added to Glaives. The damage on the other hand can be, yet it is not. Synthoceps, another Titan exclusive, increases "melee lunge range" and "Improve[s] melee and Super damage..." and works just fine with glaives.
With the statements found in the TWAB concerning Glaives, we should have access to quite a few damage buffs and armor effects. Currently, there are a decent number of consistent buffs gained from exotic intrinsic perks (introduced S19) and a few subclass fragments sprinkled about. We are still missing functionality for some subclass Aspects (Ex. Offensive Bulwark), and armor mods (Ex. Focusing Strike).
Sidenote: I'm aware of [spoiler]Vexcalibur's[/spoiler] perk [spoiler]Perpetual Loophole[/spoiler] and its similarities to Offensive Bulwark, I'm disappointed and find this to be a slap in the face.