Baldurs Gate is ridiculously simple. If you understand the mechanics, how the gameplay works, and know superficially how to assemble characters, the game becomes extremely easy on the highest difficulty. That's without imbo builds. You even have to give up some features on purpose so that the game doesn't seem too easy. I don't understand why this thread suddenly appeared. Well difficult for you? Set the difficulty down. I would even introduce another mode super hard for those who understand the game.
There are some mechanics that make the game monotonous? Then don't use them. The game gives you choices, if you choose idiotic gameplay without using your brain, you get monotony.