PvE, Staff could use a lot of work to be more functional and fun. I prefer staff for the style and asthetic, but I mostly use Scepter/Focus or Scepter/WH because it's cumbersome in OW and underperforming elsewhere. Staff weaver in particular promises to be very fun conceptually, but the impacts aren't very strong and the cooldowns are long in PvE compared to everything else in the game. It doesn't seem to work well with either Tempest or Catalyst, either.
Outside of following zergs in OW, it needs to be a weapon that can stand on its own, especially since it's the game's representative of the classic elemental mage style. To a player who loves that style like myself, running around with a sword or a hammer in Melee doesn't hit the spot.
Changes I would want:
Fire 1: increased projectile speed and 50%+ chance at projectile finisher.
Fire 2: Increased power coefficient.
Fire 4: CD reduced to 15 seconds
Fire 5: Keep channel, but drop three large rocks with knockback from the center on last hit (defiance break). High Power coefficient, last hit is strongest, blast finisher, leaves smoke field on crit in PvE.
Air 1: Change to standard small AOE around target, bigger damage. This skill is awful.
Air 2: Higher power coefficient, Projectile finisher
Air 3: CD reduced to 15 seconds, also grants fury to allies.
Earth 2: Slightly faster cast time, 3/4s instead of 1 1/4s.
Earth 3: CD reduced to 15 seconds in PvE and 20 in other game modes. Grants barrier or protection as well.
Earth 5: Increase to 4 stacks of bleed, 2 in WvW/PvP.
Fire/Air 3: Increase Power Coefficient in PvE only.
Fire/Earth 3: Burning on Impact should be 5 seconds in PvE.
Air/Water 3: Needs something, I never notice when I hit this button
This would give Staff more reactive play, more damage out of the buttons people hit, a reason to hit buttons that don't feel like they do much, more finishers to play with Catalyst, and a touch more support. It's stuck in a hybrid of damage and support from 10 years ago because it can be obnoxious in WvW. If the weapon is supposed to be more supportive, then make it more supportive, but all the skills on it suggest a damaging weapon with modest support. It simply needs to be brought into 2023.