Hey all, for some context I haven't played this game since before the expansion release where the only endgame content was playing the campaign over and over on Inferno difficulty. It's been really fun checking out all this rift content, blood shard and cube gambling, and everything added since the expansion.

Some friends and I have recently made new seasonal characters, and I'm wondering how I can push more damage on my Monk compared to my friends' Barb, Necro, and Wizard. Here's my current build for some more context: https://maxroll.gg/d3/d3planner/112217160

To get an idea of how my damage is, I'm able to comfortably solo T16 normal rift and around GR80-85ish. Anything past that, I'm unable to kill elites without a lot of death when Serenity is on cooldown since basically everything one-shots me (arcane lasers, poison puddles, etc.).

My friends' characters are all able to push GR100 however, with the wizard easily doing several hundred bil hits with meteors and the Barb mowing down enemies with Whirlwind. My damage also becomes almost nothing when we do a 4-man T16 normal rift for keys. Even with me being essentially dead weight doing what may as well be 0 damage to a regular mob, they're able to carry me through. For comparison, our Barbarian (https://maxroll.gg/d3/d3planner/533896782) can mow through a GR90 by himself (scaled to 3 players) with Whirlwind while my Mystic Allies barely contribute anything more than some CC with freeze. What am I doing wrong?

I'm following the top monk build on Icy Veins, and though I'm a couple of pieces off using Water instead of Fire Ally, most of the Mystic Ally damage should be present. Am I just missing a gem slot for Stricken? Paragon levels (we're only maybe 150 or so levels apart)? Augmenting ancients? Does Inna's Mantra just suck after a certain point and I should work on building another set or LoD Wave of Light?

tl;dr - Monk not doing as much damage as friends' characters, looking for most efficient way to bump damage up