[GSC] [Not Indexed Pages] Lost with the numbers I am seeing

I recently joined a company as a designer but was tasked with looking into basic SEO. When I logged onto GSC, I saw the numbers and was shocked. I am not sure what is the best way forward. The 404 pages are so high because those pages dont exist anymore and I did tell the management to divert the traffic to Home Page which they are not keen on. Please let me know what to do or Is this normal ? Google Link of screenshot is given below...if you need any other info...happy to provide... \----- Crawled - currently not indexed | Google systems | Not Started | 3,071 Not found (404) - 469 Excluded by ‘noindex’ tag | Not Started | 656 Page with redirect | Not Started| 269 Duplicate without user-selected canonical | Not Started | 242 Alternative page with proper canonical tag | Not Started | 89 Blocked by robots.txt | Not Started| 19 Blocked due to other 4xx issue | Website | Not Started| 1 Discovered – currently not indexed | Google systems | Not Started | 6 Duplicate, Google chose different canonical than user | Google systems | Not Started | 2