If you think sports can't have an element of luck, you've never played a sport competitively before. Show me one definition of sport that excludes activities with elements of randomness. You won't find one, because it's bullshit.
And school = sport? What? A sport is an athletic activity requiring skill or physical prowess and often of a competitive nature, as racing, baseball, tennis, golf, bowling, wrestling, boxing, hunting, fishing, etc. (Source).
Just because a term has ambiguous bounds doesn't mean anything can be applied to that term. I don't think the title of competitive gaming is important. It doesn't matter if you call it a sport, or esports, or whatever else you want to call it. It just matters that it's a legitimate competition with a level of difficulty comparable to traditional competitive activities, many of which are traditionally classified as sports.
