Windows does not kill system processes like that the way Linux does. It doesn't even have a real OOM killer, it just keeps allocating more and more page file until there's no more page file to allocate, no more pages to compress, no more working sets and other caches to clear, and then finally gives up when you try to allocate RAM. If DWM.exe crashes and you have even a small amount of storage space or RAM, something else is going on.

Given how DWM and video games both hit the GPU pretty hard, the death of DWM.exe can be anything from memory exhaustion to (GPU driver) bugs.