To be fair, the argument most often used for OTP-ing in LoL is not that you neglect developing game knowledge and macro play in favor of mastering that one cham

To be fair, the argument most often used for OTP-ing in LoL is not that you neglect developing game knowledge and macro play in favor of mastering that one champion, it's that OPT-ing eliminates all of the random barriers to entry that comes along with having to learn a wide array of champions which in turn allows for you to spend a far greater amount of time developing general game knowledge and understanding of macro play.