Because having 1 level 3 beacon is worth less than 1 level 3 vanguard banner.
The 25 RR shred definitely helps (and it is OP in its current state, so I wouldn’t be surprised if it gets booped by 
)
But IMO, the biggest benefit is the freedom of movement/no stragglers
Yeah pulling agro is a big deal. So they don’t benefit from my ele -> pierce conversion? 
No. they don’t benefit from any player stats. On the plus side, things like Aura of censure*, or vulnerbility will boost their DPS.
EDITED: WoP… lmao!
I was just looking at this build and wondering if you’d change anything for the current patch.
I think overall it’s fine as it is but you have to change the conduit to literally anything else as it was reworked (and now redundant because previous cdr for Storm Totem isn’t needed anymore).
Also i don’t recommend farming 150-170 Crucible with it. Crucible became harder, this kind of lightning melee(ish) will have hard time surviving it.
What about SR?
65-66 should be easy, 75-76 won’t be deathless though but you should get through it because of lots of passive dmg.