Either of this will work fine for SEO, both formats have the essential information that makes the URL relevant to the topic of the page.
And then have a link on each post to "genres" and "authors" archives
with filtering system on it?
Depending on how your filters are implemented this could be a bad move. Many Ecommerce sites have similar implementations: main categories, then filter attributes to drill down products further within the category.
However, often the implementation is done in such a way that the URL used for the filter is just URL parameters on the same category URL and does not give the ability to create relevant page titles, meta descriptions, headings and content for the filtered page, it just uses the same page content as the category before its filtered. Also internal linking to filter pages is usually missing, as they are often buttons, rather than links.
This means there isn't a relevant landing page optimised for the attribute used as the filter, which means missing out on potential traffic.
So if you were to use filters, make sure you create pages that you can independently optimise, as categories such as genres and authors would make ideal landing pages to capture traffic.
Some other factors you can use to base you decision on
- Whats easiest to implement for development time
- Giving yourself room to grow, could one format make it easier to scale as the site grows without having to change the logic?
- Reporting: having a structured format like the first option makes it super easier to report when you have a lot of data and a big site. You can easily use the directory as a unique identifier to quickly segment data for that category: books, drama, author, etc. and you can add them as separate entries in search console too.
- What works for users: Either format makes contextual sense and reads fine, some might say option two makes it easier to write the URL down. But who actually writes URLs down? Exactly.
