Treyarch seem like they just can't hit the sweet spot for the armour mechanic in Call of Duty: Black Ops 4's Blackout mode. After being nerfed, then getting the repair option, it is now being nerfed again, to avoid bullet sponge experience.
Call of Duty: Black Ops 4 kicked off in style as players started enjoying its numerous multiplayer modes. One of them stood out in particular, and it's Blackout, the battle royale mode. Naturally, it gained a lot of attention, which resulted in bugs and balance issues being pointed out rather quickly.
The biggest and the longest linger issue so far has proven to be the level 3 armour in Blackout. Just like in many other battle royale games, players will come across armour they can loot and increase their chances of survival - the higher the armour level, the better survivability it offers.
Unfortunately for the balance team, level 3 armour proved to be too effective at what it did so it was nerfed in the first patch, back in October 2018. It was all nice and dandy for a while, until Treyarch introduced an armour repair system, which allowed players to repair their level 3 armour after a firefight, which resulted in too many players having a pristine armour, all the time.
To address these issues, durability of both level 2 and 3 armours has been decreased in the latest patch, so now they can last about as much as a level 1 armour. The number of maximum armour plates that can be stacked has been halved, so now it is five.
Using an armour plate will now take three seconds instead of two and finally, Paladin will have better armour penetration so it will take fewer shots to down a heavily armoured opponent.
According to the developers, the nerfed version of armour will still last through a single firefight, but armour destruction will occur more frequently, bypassing those pesky bullet sponges. You can read the full patch notes on Black Ops 4's subreddit.