C1 with 7k hours. Why am I still so bad?

I want to understand how it is even possible for me to be so bad given how much time and effort I’ve put in. I get that some people have put in more time than me, but I can’t always use that as an excuse right? This problem isn’t even exclusive to Rocket League, it's the same story in every single competitive game I play.

I know that the only way I can ever hope to improve is to quit making excuses and train. I need to train more, I need to train smarter. But of course I told myself the same things 3k hours ago and look where it got me.