I believe that Weakness Arrows should be entirely removed. In my opinion Stuff like Reinforced boots are fine for pvp as it has a few downsides to balance it out, but something like weakness arrows when paired with a crossbow that has multishot and quickcharge makes it so its really easy to apply weakness to every single person on the opposing side (or atleast the most dangerous and most capable pvpers).
Weakness makes it so your attacks do -4 damage, so if you have a strenght potion (which is +6 damage) weakness 1 (-4 damage) basically negates all of the strenght from the strenght potion and makes the time to kill go up exponentialy, which makes it so less and less people die each siege. The only real strategy and impact pvpers have are the ability to kb people of the banner and into their ganks. That alongside various other things like tps going down and Resistance potions/Reinforced boots make it so it is literally not possible to kill any player unless they fall in your ganks or are a total beginner with no knowledge of potion pvp.
This paired with the safety net of ganks makes it so very few people die, and the people that do die are beginners who know nothing about the siege system/meta