If you have a lot of not function urls creating problems for site visitors, it is advisable to remove them. If you remove them from search console, they will removed from cache for shorter period of time.
There are mainly 2 types of URL errors .
Page Not Found Error ( http status code 404) : This type of error is error display that page not found because resource changed or content removed. A large number of 404 pages negatively affect crawl-ability.
Page Removed Permanently ( http status code 410 ) – If you want to remove pages forever, return http status 410 for such urls. This response will force search engines to remove pages from future crawling and indexing.
Crawl-ability is important because it affects the number of pages to be cached.