Sure... it's scary and it feels crazy to try out for a team if you think you're terrible at the game, and it's important to try out for a position that you really enjoy playing; but the secret is that you don't have to be that good. What you have to be is willing to get better.
That's not a small thing. You have to be willing to dedicate the time and effort, be willing to destroy your self-perception about how "good" you are at the game, and be willing to do whatever it takes to learn how to be better at the game with your team. And no matter how good you get, you have to be willing to try and do your best to get even better. Especially at the top tiers. You have to be willing to destroy what you thought you knew, get creative, and get even better.
And you will get better. Playing against others who are dedicated to being good gets you to be even better, the competition is simply the motivation to do what you're doing, a way of measuring how much more you can do and what you need to improve for the next time. There was this motivational quote that said, "I do not compete against others. I work to excel." It's not about the comparison, it's about always doing better than you've done before.
And, yes, if this sounds familiar to those who work in the martial arts or in competitive sports, it is very much like that; however, there isn't the emotional and physical payoffs of using or moving your body to do what you need to do. The aerobic benefits, the blood flow benefits, the physical benefits aren't there, though the perseverance and courage needed are much the same. The adrenaline fix, the intensity of emotions, and the quickness of the game is so much more, though, than real life because there's no need to hold back when I'm killing the virtual stand-in for someone else. And the intensity of killing or dying will always be elevated compared to the limits put on arts where part of the goal is to not have anyone get hurt, much less die of the actions of others in the game.
And so we walk into the darker shadows of video games. That same lack of physical activity, the watching of a moving screen instead of real life, the adrenaline rush while being completely still are all things that can feed not only depressions but anyone that wanted an excuse to neglect their real body anyway. Including, in my experience, someone with spinal injuries, someone with on-going health problems, someone who has always been morbidly obese, someone who was bullied at school and has no reason to want to go back to see people again, or someone who is losing their physical abilities a bit at a time. It's a ready escape. Easy to take, cheap to maintain, and always present for use.
Sword Arts Online, in the latter chapters, the ones that most people avoided and therefore never really got to, there was a character who was amazingly good and she was, in real life, helpless in a body that couldn't do anything at all. It's startling for me to realize that that the story reflects more than I thought was true.
But it's odd, sometimes, to find that the same determination that allowed me to get good at engineering and real life, was applicable to game; and odd to realize that just 'cause someone has those qualities for their games, that they can't always apply them to real life.
Watching the Rainbow Six Siege Invitationals, there were all kinds of people saying that they "weren't good enough" for Pro League, and in a way that was true, but in another, getting a foot on the bottom of the ladder of ESL team rankings is possible for anyone. Anyone can play in the leagues that eventually qualify for the top spots, but it takes that kind of commitment, not a certain threshold of ability.