I don’t have a link to SEO evidence at hand, but for example the industry standard SEO tutorial teaches “Shorter is better: minimizing length and trailing slashes will make your URLs easier to copy and paste (into emails, blog posts, text messages, etc) and will be fully visible in the search results.”
It’s also possible – but this is just guessing – that items in your URLs are given higher score if they are earlier in your URLs or if there are less other charactes in your URL. Search engines have been known for long to use this for titles, and it they might use it for URLs already or start using in the future.
Then there’s the obvious: If categories are important in your navigation, you want have your site links point to domain.tld/news/ instead of domain.tld/category/news/.
I didn’t bother starting to use the plugin until categories started to really matter in my site navigation.
