Yessir

What are you on shift + tab is great

You must not play competitive FPS games. This input interferes with checking the leaderboard and sprinting.

I play tf2
I've never had a problem with shift + tab

Tf2 doesn't have sprinting, so it doesn't count. What I mean is call of duty. You have shift as sprint, and tab as leaderboard. And if you are running from some enemies and you need to know your score, it interferes with your speed since it opens the steam overlay.

You do know you can bind different keys right

Yeah, but it's a meme