It's been a long-standing vanity metric. I've been in the SEO industry for a long time, and it used to matter more than it does now, slightly. However, nobody REALLY knows the true domain authority, and they can be easy to manipulate (remove high DA links once service has been offered and review is left), so that's annoying.
There's not many shortcuts to getting high quality links other than broken link building, strategic outreach and paying. I prefer paying, personally. This can be done through sponsorships, link brokers, partnerships, etc.