I'm starting to think the MC is purposefully making things harder for himself in the fights to gain experience. But since it's not a game, a single mistake may cost him his life. Thus I wonder why he insists on doing everything by only using his fists. Does it really matter? The criminal wouldn't care if he's beaten to a pulp by using fists or a baseball bat. He's, nevertheless, badly injured or dead. So, it's only about the MC's own satisfaction.