there is a big problem in your calculations. the problem is that devoure and rageblade were for the most part magic damage and new items are mostly physical. so the dps. is a lot lower because every champion in the game has at least twice as much armor as they have in magic resist. also people tend to buy more armor items even if your building hybrid damage.
#2 you realize that and i know you do your just making a statistic on a certain situation. that early game you have a lot less hp than late so the dps is much lower for the new items.
on average over a whole game the dps i'd say from old guninsoo to new. just items. is down by about 50%. its a stupid number. but thats what i estimate it at. i think the items alone. old vs new. do half the damage at the moment we buy them at. the old rageblade gave about 35-40 or more magic on hit. and more attack speed and stacked faster.
phantom hit used to proc sooner. because u didn't need to stack anything.
devourer has 60 magic on hit whenever you max it.
why is that font bold?
i just put a number sign
overall though counting everything i think yi and jax would do about 25-35% less damage than they used to. especially for yi since jax actually uses the ap in rageblade on hit so he doesn't care as much about the stat scaling on hit that got removed. thats in a full build fashion. at 2 items i think the damage might be even lower on a sated devourer