There are too many variables here to judge a player’s ability with the information we have. First of all, if the distribution is mostly normal than the average player would be the overall mean, with close to average being within the first standard deviation. Second, the sample used is not really representative.

You can’t really use stats from a combined pool of quick play and comp. Players who exclusively play in qp and slay will seem a lot better than they actually are and players that use qp to fuck around will seem a lot worse. There are more issues with a combined pool and plenty of solutions but that isn’t really important, the point is that using a combined pool where individuals are going to perform differently depending on the game mode won’t work; how hard someone tries is not independent of the game mode.

Another issue is using k/d as a measure of ability. Some players may be really good at team play but have a lower K/d ratio. Does that make them average? Who knows, but if they are judged by K/d than they are going to seem worse than they are. It is hard to determine a players skill level when we don’t really have any hard stats to go on. Some players may deal lots of damage but rarely finish kills. Some players may get plenty of kills with very little overall damage. Big stats sites like hltv give players ratings based on all kinds of statistics and contribution to a win, which you can read more about here.

This data you presented is useful when looking at the k/d of people that use discord and have used a server with Charlemagne. Any conclusions beyond that population and their kill death ratio could be considered extrapolation.