The lead post in this series is Mastering Topical Authority: A Comprehensive Guide to Boost Your SEO.
At the risk of giving a vague answer, page authority is kind of important to SEO, in some circumstances.
I say that because while it is considered to be an important metric, it’s one of many.
Since I’m not aware of any specific experiments that show how important it is relative to other metrics such as domain authority, I relegate it to “it depends”. More on that below.
In case the difference between domain authority and page authority is not at the front of your mind right now, domain authority is an indication of how well pages on the site are likely to rank, and page authority is an indication of how well a specific page is likely to rank.
But, if you focus excessively on page authority, that may cause you to focus too little on other important aspects of SEO, such as external validation (links and brand mentions).
So yes, it’s important, but the consensus in the SEO community is that’s it’s not important enough to devote too much time to, with one notable exception.
If you have a specific page that ranks at the top of page 2 for a specific search query, then page authority for that page becomes VERY important.
Because if you can push that page onto the bottom of page 1, that’s a win!