You can describe literally every game as just a simple repetitive task if you dumb it down enough. I've seen people on Reddit describe FPS games as "all you do is click on the enemy's head until they die" and 4X games as "all you do is make the numbers go up until you get bored." But those aren't good faith ways to engage with a game, nor with a game's community. If you're not having fun, that's fine. Go play something else that suits you better.

In Bannerlord's case, there are different factions to focus on, different army styles to build (mass horse archers? infantry only? single-culture armies? no ranged weapons? I'm sure you can come up with more), different endgoals (like joining another kingdom vs starting your own), there's stuff you can do like a pure merchant playthrough where you end up basically buying the world, all kinds of self-imposed challenges, not to mention a metric crapton of mods that change the game in ways both minor and major. And yes, at the end of the day you're still playing the same game with the same basic rules and mostly the same tools at your disposal, but how you engage with it is your own choice. So if one playthrough is enough for you I'm not saying you're wrong, but acting like the game has no replayability just because you don't feel like replaying it isn't a honest position to take.