I was getting big mad over trying to grind a set for my C6 Noelle, and have been kicking myself for using a 4* Geo Dmg Goblet with double crit for fodder because it's exactly the piece I needed to finish this build. Curious, I decided to take a break from endless Guyun to actually see how much of a difference 4* vs 5* actually makes. I used Xinyan as an example because she's who I already had open on the calculator when I decided to do this. There's nothing deeper to it.
5* Artifacts vs 4* Artifacts
C0 Lv80 Xinyan, All Talents Lv 6, R1 Lv80 Serpent Spine, No Stacks
2 Piece Bloodstained
2 Piece Gladiators
Atk%, Phys Dmg%, Crit Dmg%
All artifacts at max level for rarity.
No Sub stats Average DPSFull 5 *= 5270
Full 4*= 4191
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Single 4*, Rest 5*---------------------------------------
Feather= 4998
Time Piece= 4999
Goblet= 4844
Circlet= 5083
-------------------------------------
Two 4*, Rest 5*------------------------------------
Feather + Time Piece=4724
Feather + Goblet= 4595
Feather + Circlet= 4821
Time Piece + Goblet = 4595
Time Piece + Circlet = 4821
Goblet + Circlet = 4673
-------------------------------------
Three 4*, Rest 5*-------------------------------------Feather, Time Piece, Goblet = 4345
Feather, Time Piece, Circlet=4559
Feather, Goblet, Circlet=4431
Time Piece, Goblet, Circlet=4191
Sub Stats, Atk 4.1%, Crit Rate 2.7%, Crit Damage 5.4% (Replacing duplicates with Atk 16)Full 5*= 6815
Full 4*= 5427
Full 4* with one upgrade to each Atk sub stat, doubling value= 5934
-----------------------------
Single 4*, Rest 5*-----------------------------
Feather= 6493
Time Piece= 6493
Goblet=6264
Circlet= 6518
-------------------------
Single 4* with one Atk Upgrade, doubling value, Rest 5*---------------------
Feather= 6605
Time Piece= 6558
Goblet=6367
Circlet= 6625
-------------------------
Two 4*, Rest 5*--------------------------
Feather + Time Piece=6172
Feather + Goblet= 5969
Feather + Circlet= 6210
Time Piece + Goblet= 5969
Time Piece + Circlet= 6211
Goblet + Circlet = 5992
-------------------------------
Two 4*, with one Atk upgrade each, doubling value, Rest 5*---------------------------------
Feather + Time Piece=6348
Feather + Goblet= 6174
Feather + Circlet= 6424
Time Piece + Goblet= 6131
Time Piece + Circlet= 6380
Goblet + Circlet = 6188
--------------------------------
Three 4*, Rest 5*------------------------------
Feather, Time Piece, Goblet=5673
Feather, Time Piece, Circlet=5903
Feather, Goblet, Circlet=5709
Time Piece, Goblet, Circlet=5709
-----------------------------------
Three 4*, with one Atk upgrade each, doubling value, Rest 5*-----------------------------------
Feather, Time Piece, Goblet=5938
Feather, Time Piece, Circlet=6179
Feather, Goblet, Circlet=6004
Time Piece, Goblet, Circlet=5963
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The reason I decided to calculate with no sub-stats is that they are a variable we have next to no control over, so seeing what the raw numbers look like without them helps put things into perspective.
Next, I decided to put an “ideal” sub-stat setup, just for the sake of comparisons. Make no mistake, having double crit and atk on every 5* piece in your set is probably harder than rolling a C6 Mona.
For those that don't know, the actual sub-stat value is itself a random variable pulled from a pool, with 5-star artifacts having the potential to have a “base” sub-stat higher than a 4 star. The specific numbers I chose for the sub-stats are variables shared between 4 star and 5-star artifact pools. Well, technically there's a 0.1% difference between a few, but I didn't consider a fraction of a percentage to be enough to skew the results significantly. This isn't meant to be 100% accurate anyway, just something to get a general comparison between 4 stars and 5 stars.
The reason I had most of them kept at their level 0 variable is that when sub-stat levels up, it's actually random how much it goes up by. Trying to account for that is a fool's errand. I calculated for a level up on the atk sub-stat for the 4 stars to give a nod to the fact that you can be a lot pickier with your sub-stats on 4 stars. Whereas, with a 5 star, sometimes you've just gotta take what you have cause it's the best you'll get, even if it Def, Def%, HP, Crit Rate%.
You're free to make your own conclusions based on this. My personal conclusion, however, is as follows.
Gamers aren't oppressed, but they absolutely deserve to be.