I think the reason Mushoku Tensei starts more arguments than any other isekai is that it refuses to make Rudy a clean hero or a straight-up villain. The show lets you see his worst habits up close, it lets the people around him call him out, and then it still expects you to stick around and watch him grow. If you need your main character to be clean, that's going to feel uncomfortable, but that discomfort is the whole point of the story. This just never gets boring to talk about #MushokuTensei