"Playing with 300ms is not the problem"

You are ruining the game for 9 other people when you are knowingly playing with that ping every game. Playing with 300 ms IS A PROBLEM.

A) Fix it. Move out of antarctica or get new internet. B) use a wired connection. don't play on wifi in your basment/attic etc. C) Don't play when you know you have a ping so awful that playing at any competitive level nearly impossible.

I know YOU may want to play, but i tee your team doesn't want you playing with an unreliable internet connection. The enemy team might enjoy a free win, but they might also dislike a challenge-less lane playing against you and your 300ms.