It's like, despite being influenced/inspired by wuxia, monks in dnd are so weaaak in comparison with standard wuxia... it's like, if you play a monk, you can only be a mook-level character in a wuxia story until you're like level 20, at which point you're just A-tier, not even S-tier
There are plenty of isekais that have the MC go on degenerate freaky stuff. As isekai is a medium for living out fantasies, then there is no problem for John Brown maxxing.