Why do people call this game a skillbased game?

I can understand that the game is skill based and requires a lot of teamwork if you actually have 4 friends to play with in a team and you are playing to win. Totally understand that.

But this game is not like CS:GO were you can have 4 people AFK and you can still win the game.

In this game, if you have just 1 afk in the team, you will lose about 80% of the time. The AFK players do not get banned, and if they do get band, they can just create a new account. People are in general not nice and most people tend to just do their own thing.. in a team based game.

And i watched some streams to learn, and it seems like its not just me having "bad luck" with people going afk every third game. In fact, the only streams were people do NOT afk is in high tiers, like high diamond. but for people like me, who don't wish to spend 20-40 hours a week climbing a ladder were 33% of the time i will have a 80% likelihood of losing but just want to play a full 5 v 5 game to try to get to a point were i get to play with better than average players who do not flame and do not insult and do not troll or afk.

I guess i could get on a luck streak were i do get good synergy in the team were i can learn from mistakes and improve my ratings. Because if you flip a coin a infinite number of times, eventually you will get a series of 100 tails or heads in a row. But in no way is that skill based, so i do not understand why people say that it is.

But hey, the concept of the game is great, i think once Riot gets the game out of Alpha and into beta were they have a proper banning/kick system up and running, i might even try to get on the ladder again.