If content was intentionally removed without an equivalent replacement, return 404 or 410. A useful error page can offer navigation without changing every missing-page response to 200.
If content has genuinely moved, consider a permanent redirect to its replacement. Many incoming links do not justify redirecting every deleted URL to the homepage or an unrelated page. Update internal links and sitemaps as well.
A soft 404 typically looks successful at HTTP level but is judged by Google to contain an error or empty content. A URL classified this way in Search Console is excluded from indexing. Repair missing or failed content when the page exists, or return the appropriate status when it does not.