*The following page is geared towards Havoc Demon Hunters, as they are the most effective and popular choice for running dungeons at 70*
POV: You've recently returned from a brief hiatus, logged in to your 70 DH, and queued up TBC timewalking dungeons with a full group of 5.
WHERE'S MY DAMAGE?!
With this most recent patch, Blizzard finally decided they've had enough of the Reddit threads and confused level 80s- below max level, Timewalking dungeons (not normal dungeons) now scale mob health dynamically based on your primary stat. Yes, even the fabled low-level evokers with iLvL 206 gear are unable to one-shot dungeon trash. Bosses have even more health than ever before. The more primary stat you have, the chunkier your NPC enemies are.
We can still work with this, it's not joever.
Thanks to community member warcraftisgood, we know more or less how this scaling curve works (scroll to the bottom for mathy maths).
We can see that the greatest "bang for your buck" in terms of primary stat is right around 8345 for melee specs. We want to get as close to this as possible.
Secondary stats, for the moment, do NOT affect mob health.
Direct attack power and spell power buffs do NOT affect mob health, but agi/str/int ones do, including random procs.
Cloth gear gives no agility or strength, therefore we can use a combination of armor types to manipulate our primary stat without affecting secondary stats.
Trinkets play an important role. Currently, the most popular choice is Fyrrak's Tainted Rageheart paired with Augury of the Primal Flame (both from Amirdrassil final boss). Get these on mythic if you can; join a transmog farming group.
If you played in Dragonflight S4, Beacon to the Beyond is another solid choice, but new drops are not worth using due to item levels.
An easy on-use attack power trinket is from WoTLK timewalking, Sphere of Red Dragon's Blood (iLvL 415, 1,611 AP @70).
A PvP trinket is advisable for dungeons/bosses with hard stun mechanics.