For MMORPG kingdom building, we have The World Online. The other one is not quite the world-building, but I think you'll like Rakuin no Monshou.
The MC is a retired warmage living in a remote area of the kingdom as spellmonger (someone who sells sells spells to villagers and farmers) when goblin ish creatures invade with magic stones that greatly enhance a mages power. MC manages to acquire one and have it purified by the equivalent to elves. His stone can be used to purify other stones. So with the offer of stones he gathers old mage friends to try and defend the territory but they are overwhelmed by numbers and have to flee with the people. The second book is about him convincing the Duke to send troops and him leading a troop to defend against the invasion while the dukedom prepares forces it ends with the war a stalemate and he gets a fief. Book 3 onwards is about him developing his fief, Being caught up in nation level politics, Forming and running a mage organisation made to handle mages with the magic stone, Warring with his neighbouring lords, Setting up defences against the invaders, Being bothered by gods, Being bothered by elves, Being harassed by a nasty mage control organisation that serves only the King (but there has been no king for centuries) who want to lock up the magic stones not caring that about the war they are needed to fight, with added on mad mages and undead elves and lots of other etc.
Oh it certainly is. I mean the author constantly goes over his previously made explanations in multiple chapters like we haven't heard it before. One of the most recent things he did was go to the store and casually bought a hundred thousand slaves. How the fuck does someone stock one hundred thousand people like its no big deal? Not to mention that there were a dozen slave trader shops on the same street.
Hmm how about "Bringing The Farm To Live In Another World".it pretty long but it is a good novel in my opinion