Do you happen to use memory resource limits? I used to run Firefox under some, like everything, to prevent it from potentially making the whole system unresponsible, and at the same time had frequent cases of Firefox showing random visual corruptions and crashes. At some point I realized that it was because it was running out of memory, and didn't check malloc failures, thus just continued to run and corrupting memory. (That was some 6-8 years ago, maybe Firefox does better now?)

You were seeing issues from the graphics driver, not Firefox.

Any memory allocation failing within the browser forces an instant crash unless the callsite explicitly opts in to handling the allocation failure.

"Check malloc failure" is an opt-out feature in browsers, not opt-in. It's the same in Chromium. Failing to check would cause too many security issues. (One more reason new stuff tends to prefer Rust, etc)