The new Linux port of Metro Exodus sadly came with a rough launch but for AMD GPU owners it's set to get more playable, with a fix in the Mesa RADV driver now merged. I've been following this quite closely, first posting about it on Twitter yesterday after being told about it.
What's the issue then? Well, this Vulkan port caused a lot of RAM to be eaten from a leak, it got real hungry really fast. A bug report was made with Mesa on April 16, and as of April 19 the fix was merged in - a pretty amazing turn around and shows again the power of open source drivers for solving issues.
Since it's merged it will for sure be in the Mesa 21.2 release, and should also be backported to the next stable update to the current Mesa drivers - hopefully the upcoming Mesa 21.1 release too which would be ideal.
For NVIDIA users, making sure your drivers are up to date is a good idea. My own NVIDIA system seemed more stable with Metro Exodus on the latest 465.24.02 release. There's still crashes in the desert area, but after plenty of research this appears to be very common on even Windows. Adjusting graphical settings down to medium for a bit gets around the areas to cause the crashes.