Personally, I used to crave kingdom-building novels too, but then I realized that web novel authors simply just can't write good kingdom-building novels because it's a genre that requires deep knowledge and insight. So I learned to just play Paradox games whenever I have that craving.
The solution is fanfiction, I follow many authors here who are better than web novelists. Well..there's plenty of garbage fanfiction same as web novels, so it's more accurate to say these authors aren't constrained by tropes, cliches, fillers and deadlines. https://www.fanfiction.net/u/9071421/
Engineer Hank Morgan transmigrates from 19th century united states to 6th century England, king arthur's era, after being hit on the head. https://en.wikipedia.org/wiki/A_Connecticut_Yankee_in_King_Arthur's_Court It's a funny comedy about how a time traveler uses his knowledge to face slap people of the past, but becomes weirdly and suddenly serious at times, exactly like a webnovel story. This is in the public domain. You can read it for free on gutenberg. https://www.gutenberg.org/files/86/86-h/86-h.htm
Also, another great kingdom building webnovel is https://en.wikipedia.org/wiki/Illumine_Lingao Quoted from the wikipedia article - "The novel is praised as the "encyclopedia of time travel" among readers." You don't need deep knowledge and insight if you can just ask your millions of readers to offer their knowledge and insights on historical facts and use that as assistance while writing the novel, which is kinda what the author did. This novel isn't finished yet, but it's been written since 2009, currently at 7.7 million characters/words so should be a decently long read.
It's mostly a matter of how much work the writer is willing to put into the story. Yeah, it's rare for amateur writers to go to such lengths but it is out there. This is a decent example. I'm reading this book right now, and you can just feel the amount of work the writer put into researching the time period and making it come to life. It's just full of details that are impossible for a fictional setting to match. There's even better stuff out there but I don't know if any of those are translated. However, any book with "realist" in the title is going to suck.