Most sims are for single target patchwerk style fights (unless you tell them otherwise).
If you are trying to reach your sim dps, you should focus on tuning your gear for single target. Right now your gear is pretty out of sorts for that kind of sim.
Here are my recommendations for single target improvements to your gear:
Azerite Gear:
Change your chestpiece to Ruinous Bolt - Gutripper
Change your shoulders to Liberators Might - Gutripper
Change your helm to Twist the knife - Overwhelming power
Secondaries: Your current stat weights (according to sims) are:
MH Weapon dps > Agi > Haste > Crit > Mastery > Vers
Talents:
Elaborate Planning
Master Assassin (You don’t have enough haste, or the right traits to make full use of subterfuge, also twist the knife works great with master assassin)
Vigor
Iron Wire
Poison Bomb
Weapons & Rotation:
Nothing improves your dps as fast as weapons or proper rotations, regardless of what your secondaries are at. Run warfronts, arathi rares, normal/heroic uldir (use bonus rolls on mother/Zul) etc and get some weapons asap. Highest item level in your mainhand, always.
Rotation for Master Assassin (single target):
Garrote, Mut (till 4+cp), Rupture, Vendetta/Galecallers, Toxic Blade, Mut (till 4+cp), Vanish, Envenom, Mut (till 4+cp), Envenom. Then refresh bleeds when they reach <6 seconds and squeeze in as many envenoms as you can inbetween refreshing and use Toxic Blade on cooldown.
Rotation for Master Assassin (aoe):
Garrote, Fan (till 4+cp), Rupture repeat fan+rupture onto at least 3-4 targets. Then start using Toxic Blade/fan/Envenom onto a priority mob until you need to refresh ruptures.
Last note: GET DARKMOON FATHOMS (really? Blockades?) Fathoms is the single best trinket a rogue can get until 385 level trinkets and even then they are sidegrades. That alone is a 1k dps upgrade for you.