Are you fucking serious? I pity you if you think Rom-coms have to be so bad. There are tons of them with mature characters too. In this one the author is playing with the gap moe (Strongest Knight v/s Behaving like a kid).
And this premise is getting old. He has basically run out of ideas and...
Why do authors even start harem wars when it's obvious they are going to get backlash for it? Especially in Komi San. He could have kept it simple went ahead and introduced Manbagi. I'm already reading like 100 harems I don't need another one thanks.