By "we" I'm really thinking of all earth based life/intelligence, rather than just humans as they exist today. But yeah if humans self-delete in a way that doesn't involve being replaced by something similarly capable (for instance a planet of the apes type scenario), then it's probably going to be a lot longer than a million years before we recover, which could start to erode our cosmic timescale head start over life elsewhere in the universe. So we really shouldn't do that just yet.