Whether you should redirect or add content to the 47 pages depends on the specific circumstances and goals for those pages.

Redirecting:

When to Redirect: If the 47 pages have low-quality content, are outdated, or are duplicating other content on your site, redirecting might be the best option. Redirecting these pages to more relevant, high-quality pages can help consolidate your site’s authority and improve user experience. Additionally, if any of these pages are receiving low traffic and you have no plans to update them, redirecting can prevent them from dragging down your overall site performance.
SEO Consideration: 301 redirects are ideal if the content is permanently moving. This allows you to preserve most of the SEO value from the old pages.
Adding Content:

When to Add Content: If the pages in question have potential but lack sufficient depth or relevance, enhancing them with additional content can be beneficial. By updating these pages with more comprehensive, valuable information, you can improve their ranking potential and better serve your audience’s needs.
SEO Consideration: Ensure that the new content is well-researched, relevant, and optimized for the target keywords. This approach helps maintain or even improve the rankings of these pages.
Recommendation:
Evaluate the current performance of each of the 47 pages. If a significant portion has strong existing backlinks or decent traffic, it may be worth investing in content updates. On the other hand, if the pages are weak and have little SEO value, redirecting could be a smarter strategy.

It might even be a mix of both approaches, depending on what you find during your evaluation.