It's one of the dumbest trends in PC cases of late. Remember the old days when side panels had fans that would do a pretty good job at cooling down your GPU? I remember my NZXT Tempest - "The Airflow King" (they need to release a modern version!). The 120mm side panel fan took 7-10 degrees off the GPU. But now I struggle to find a decent airflow oriented case because trends like tempered glass panels, closed off front panels and PSU shrouds have taken over.