Exclude All Excluded Pages From Google
You have every tenable reason to exclude all excluded pages from Google.
Probably, these could be pages that are only useful to readers (Such as login or signup pages and those that contain plagiarized content), but neither to Google nor other major search engines.
Now, let's take a look at excluded pages below.
Below the excluded page chart, you will find out why those pages are excluded from Google's indexed pages.
Now, let's go into analysis.
Page with redirect: This redirects to another page. And it's very okay. If there are no internal links that may be related to that page, indexing will not be done on it at all.
Discovered - Currently not indexed: These are pages that have been crawled, but have not yet been indexed by Google.
Excluded by "Noindex" tag: The "Noindex" tag is performing its own functions well enough. It's all excellent.
Crawled - Currently not indexed: These are crawled pages in Google which have not been indexed due to cogent reasons.
The main reason those pages were not indexed will not be specified by Google.
Experience shows that such pages are not suitable to appear in Search Engine Result Pages (SERPs).
Therefore, how would you get this fixed?
Improve page quality for such pages.
For instance, if the affected page does not have quality content, try and modify it to make it fit for indexing. If it contains plagiarized content, try and make it 100% unique. For a category page, try and add some content to make it suitable for indexing.
Alternate Page with proper Canonical tag: A Canonical URL ensures that an alternative version is sorted out for such pages.
Jenny