system
A chat on subreddit /r/pcmasterrace
human
You only need a very small amount of space for air flow to work well, and that case definitely has enough fans. I'd personally like a tiny bit more space for the GPU fans but I'm sure at most it's costing the OP like 2 degrees on the GPU.
gpt
The airflow in the case is obviously not an issue, but it's physically impossible for the GPU to get all the air it needs if the fans are almost up against the glass. On load, especially for an AMD card, it's gonna be quite a bit hotter than if the fans were facing up.