Rage needs some balance adjustments.

2 things:

Losing the attack speed from rage feels really bad. Attack speed plays a huge role in making melee feel fun and responsive. It gives you mobility with shield charge, leap slam, whirling blades. It lets you kite, it makes it easier to land hits while avoiding ground degen and attacks. Before 3.25 it was always a big step in early game progression that made melee feel better to play.

It needs to decay much slower. Right now it completely depletes to zero in most boss phases. It decays if you have to wait for a league mechanic to spawn. It decays if you need to run around for a couple seconds in between mob packs. Its almost pointless to consider using it for mobility with the movement speed rage mastery and berserker crave the slaughter notable. Right now investing into decay reduction takes a significant number of passive points and only delays it by a couple seconds.

Decay reduction wouldn't do anything for something like Sirus going into the sky or maven doing her memory game...

That would require decay reduction of like nearly a minute...

Its just up constantly in mapping, youd have to do something really wrong to have it deplete....

So....

What boss phase are you referring to? I feel like most of them are a bit of a stretch to ask for rage reduction like the ones listed above.

No rage depletion issues here, and im on a slow ass slam build as well. What character of yours is experiencing this?