I see lots of people asking what they should upgrade first, or asking if the relic+1 is even worth it since it "only adds 1 weapon damage".
But real talk, that has a lot of words and graphs and ain't nobody got time for that, so let me break down the salient points for you real quick.
Here's the damage formula for skills.
(Potency/100) x [((0.0032 x STR + 0.4162) x WD) + (0.1 x STR – 0.3529) + ((DTR – 202) x 0.035))] x (1 + (0.5 x (0.0693 x CRT – 18.486)/100))
Interesting things to note, potency is a multiplier. 200 potency attacks hit 2x as hard as 100 and 300 potency attacks hit 3x as hard.
Here's the formula for your auto attack. It's pretty much exactly the same except instead of "potency" the first term is just auto attack listed damage divided by weapon damage.
(WAA/WD) x [((0.0032 x STR + 0.4162) x WD) + (0.1 x STR – 0.3529) + ((DTR – 202) x 0.11))] x (1 + (0.5 x (0.0693 x CRT – 18.486)/100))
So anyway, that looks complicated and you don't have time to plug stuff in there and check out how it behaves, so I saved you some trouble. My Bard is relic geared with almost full darklight (missing like 2 pieces) and here's what the equations look like for her.
Current Stats:
[((0.0032 * 425 + 0.4162) * 40) + (0.1 * 425 – 0.3529) + ((224 – 202) * 0.035))] * (1 + (0.5 * (0.0693 * 452 – 18.486)/100)) = 121.28
+1 Dex (primary stat):
[((0.0032 * 426 + 0.4162) * 40) + (0.1 * 426 – 0.3529) + ((224 – 202) * 0.035))] * (1 + (0.5 * (0.0693 * 452 – 18.486)/100)) = 121.52
+1 DTR:
[((0.0032 * 425 + 0.4162) * 40) + (0.1 * 425 – 0.3529) + ((225 – 202) * 0.035))] * (1 + (0.5 * (0.0693 * 452 – 18.486)/100)) = 121.32
+1 CRT:
[((0.0032 * 425 + 0.4162) * 40) + (0.1 * 425 – 0.3529) + ((224 – 202) * 0.035))] * (1 + (0.5 * (0.0693 * 453 – 18.486)/100)) = 121.32 (this does not factor in the added bonus crit provides Bards where when my DoTs crit I get free Bloodletter procs, so crit is slightly better than this number shows).
+1 WD:
+1 WD: [((0.0032 * 425 + 0.4162) * 41) + (0.1 * 425 – 0.3529) + ((224 – 202) * 0.035))] * (1 + (0.5 * (0.0693 * 452 – 18.486)/100)) = 123.17
So in summary, for someone who is almost full dark light with a relic weapon:
1 DTR/CRT* = .033% damage increase
1 DEX = .2% damage increase
1 WD = 1.55% damage increase
Or in other words, 1 weapon damage is worth about 8 primary stat, and 1 primary stat is worth about 6 secondary stat, so 1 weapon damage is worth almost 50 secondary stat.
TL:DR: Weapon damage is an order of magnitude better than your primary stat which is an order of magnitude better than secondary stats. You want to upgrade your weapon first.
