Yup, they sure are annoying. In most cases they're either catered for MC only despite being central parts of the world for at least a few millenia or are exclusively for MC to teabag the powerscaling.
My problem is that most of those "systems" try to emulate D&D, DQ, MMOs, etc. while totally ignoring that the reader isn't the one controlling the progression. They want the reader to feel like they're playing the best game ever, only destroy that illusion the moment writing continues.
Let's look at the most standard of RPG systems ever:
-You start with 6 to 12 stats
-a class list that gets unneccessarily long to show how awesome a character is
-then a needlessly long list of skills the character almost never uses
-titles that are only there to brag
-maybe even a convulted deity or blessing system as well, just so MC and party can get even more OP than they already are
The problem is most of it is just bloated background noise and almost never has any relevance outside of being mc guffins or deus ex devices.
And don't get me started on the action in those novels. Most of these ignore the hard rules they previously established to make the writing more interesting during action scenes.
The actual way to write within a system novel would need to be like this:
"Heroic Hero (Title) blessed by too many gods to list (blessings) Prota Gonist <Level 420> blocked the 69 strenght attack of the Ordinary quality Canis Lupus Magicuzwhythefucknot Wolf <Level too loe> with his 112435465768579680seggs95847365267384695706809584736 trillion defense, he then used his 1234567890987654 agility to use his High Quality Epic Longsword of Epciness+420 to us a strenght 999999999999999999999999999999999999999999999999999999 attack and drop its HP to -99999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999999."
And that not only looks shit, it reads worse than even the writing assignment of a primary schooler.
But my main problem is that people other than MC are always accepting the system as a given, never questioning it, never actively trying to go against or outright ignoring it. When the system says "Goodking the Pure's class is War Criminal" despite there not being a war or the person never commiting crimes, then PLOT and suddenly Goodking the Pure does both war and crimes because ThE SyStEm dOeS nOt NeEd InDiViDuAlS oNlY PlOt DeViCeS.