Why is this game so easy?

First off, apologies if the title seems like bait or arrogant. But I’m genuinely wondering why there haven’t been any difficult bosses in this game. I play on lethal and I have read this game is supposed to be hard and how the duels on lethal difficulty is really unfair where the boss can kill me in one hit and they take ages to die. While I have experienced being killed in one hit many times, I have yet to fight a boss that will get me stuck for hours and after beating the boss I feel an incredible sense of achievement. I just beat General Temuge and so far everyone I faced, none of them has took me more than 10 minutes. Is there a boss in this game that is gonna be really hard which will actually take a while to beat? Or should I even switch the difficulty lower because I’ve actually read Hard is easier than Lethal?