For most website owners, several “rankings” are important depending on their objective and target audience. Sites that primarily get paid for advertisements or sponsored posts and reviews may give more importance to their Page Rank because some advertisers prefer to work with sites that have a high page rank for backlinking purposes. If more sites with high Page rank link to their site, it somehow shows authority to their site in the eyes of search engines.
Other site owners give more importance to traffic, especially if they are earning through advertisements which are based on number of impressions or clicks. High traffic increases the opportunity for sale or the exposure of the products advertised on your site. Placing well in Search Engine Result Pages (SERP) also help to increase traffic.
One way to succeed in landing the top results on SERPs is through Search Engine Optimization. Some sites hire a professional search engine optimizing company to help find the best keywords for their products. By knowing what most people search for, they can work around it to make your site land on the first page of search engine results. Being on the first page or the top 10 links of search engine results page have a big impact on being clicked by web surfers.
There are other factors that may be important for other websites aside from Page Rank and Traffic of course. Ranking priorities are also different for blogs and websites. It’s just a matter of knowing which one is more important for you and start working on it.
I’d prefer getting (quality) traffic than PR. But the only way to build traffic is to consistently write good posts which would eventually lead to a better page rank.