It is crazy just how much many "professional" SEOs rely on these metrics. I would not say to just ignore them all the time, but even if they were accurate they are not updated in real time. Moz might take a few months to find new links. You might see a domain with a DA of 0, but next week it will be 30 once they push out an update. Despite that, people are using these metrics to determine things like if their links are good or not. I wonder how many good links have been removed or disavowed because they didn't have the proper metrics???