Presumably because people have used actual fuzzers and not found these bugs.

Solving bugs in Firefox is quite impressive.

By what?

With Discardables. When Blink's allocator detects a fault in a memory section it swaps it out for a new one, and taints the old so it is only reused when no more remains.

Live objects get swapped between Discardable buffers quite frequently. They're not expected to stay at the same position in memory.

Politicians don’t have to be dumb.

Bugs in the system libraries?

It is if you're being pedantic.

In this case someone is making a non-libre project with it.

Yes.

Electron?

This. The issue is not your battery but something running in the background.