You forgot to mention Ancient weapon level which is rng based in korea and gives ridicolous amounts of stats and costs redicolous amounts of oils.
When we will get it ill guess we wont get the RNG version and it will cost even more oils than a max soul since the stats added to the weapon and soul.
We also will get soulshild psyches which will boost stats even more.
We get more and more items we need to farm while materials get more and more reduced.
Back in time we had Weapon, Ring, Earring, necklace and belt, but we also had transformation stones for every region like viridian cost, cinderland, moonwater and we needed mats for every specific region, You start at viridian coast, you had to farm your mats at viridian cost to upgrade your stuff until you reached cinderlands. here you need other stuff for upgrading untill you reached moonwater and so on. you needed way less moonstones, soulstones, etc. and had way more ways to farm your stuff, like fraction dailys for soulstones, SSE for moonstones.
Now you need moon-/soulstone crystals, sacred-/elysian orbs for everything, for your weapon, ring, earring, bracelet, necklace, belt, gloves, soul, heart, amulette, pet whil you only have very few spots to farm them
Even MSP is not realy worth doing anymore, at least stage 4,5 and 6 cause sacred orbs are so expensive, you better sell them instead of buying keys, because if you dont get an evolved stone you make a loss compared to the price of the items you spend and you get.