Content quality could be why some pages are excluded in Search Console!
Google search console (SC) is an indicator of how your website is performing and allows you to draw a lot of insights about what changes you need to make to rank better. One of the tabs in SC lists the excluded URLs. There are a few reasons why some pages may be listed as excluded, but some of them which are perfectly indexable, Google simply chooses not to index them!

As John Mueller said in Google webmasters, May 15 hangout session, the reason why some pages may not be indexed has nothing to do with the Google core algorithm update on May 2020, but rather with the quality of the page content. 24:27 / 55:01
Improve web pages with low-quality content
In these situations, rather than panic, take a look at the overall content on your website, especially low quality pages. There are a few things you could do:
- Rewrite some of the content with user intent in mind and focus on providing value by doing an in depth topic research. More on delivering valuable content to your audience here
- Analyze the overall online activity, sales, customer reviews since the content was first posted, and look for ways to enrich it by linking it to actual customer experiences.
- Add visuals – Images are a powerful way to keep the reader engaged. Name your images with a descriptive title and add alt tags (an alternative descriptive name in case Google can’t locate your image).
John’s advise is to combine those pages with your high quality pages to improve the overall content quality. Google will most likely index pages that provide value to users.
Take a look at a few ways and strategies to help you create awesome content
If you need help with understanding the data from Google search console, your local SEO consultant is always available to provide training and guidance. Drop me a message.