You never realize how many weird rules, weird exceptions, ambiguities, and complete redundancies there are in this language until you try to teach English, which will also probably teach you a bunch of terms and concepts you've never heard of. Know what a gerund is? Then there's things we don't even think about that challenge even advanced foreign learners, like when you use which articles: the/a.

English popularity was solely and exclusively driven by its use as a lingua franca. As times change, so too will the language we speak.