Matchmaking overall inconsistent?

I am sorry, i know this topic is discussed to its death i have not yet seen a post talking about this specific issue (i probably missed it tbh), but why on hell is it possible to have a consistend winrate of 35% over ~100 Games and then a sudden increase to a winrate of ~60% for the next 100 games? I am not a good player and i am fine with winrates of ~45% If atleast it would be somehow consitent?

Are there any factors i might be missing? Is it just bad luck? A hint from WG that they want you to spend money? Are there any tips from people knowing what i am describing and have some advice for me?

There are times my curser hovered above the uninstall button several times.

I Hope i do not break any karma rule (Long Time lurker) and this post is not perceived as toxic, if so i am sorry.