Alvaro Gómez

This plugin restricts access for Authors and Contributors so they can only see their own Media Library uploads.
This has two main uses: Make it easier for Authors to locate their own uploads when Media Libraries grow very big and prevent Authors from using or downloading media that belongs to other users.
Admins and Editors will still be able to see everyone’s uploads.

Restrict Media Library Access

Muy útil

This plugin works fine in WP 5.7.1 

It's just the example code from the official WP docs for the ajax_query_attachments_args filter, with a line added to check if the current user is an administrator. It's very simple.

There's no reason this plugin shouldn't work in an up-to-date WP installation

works in WP 5.7.1

Restricts access for Authors and Contributors so they can only see their own Media Library uploads.

MartinCV

This plugin allows you to hide any posts on the home page, category page, search page, tags page, authors page, RSS Feed, REST API, Post Navigation, Native Recent Posts Widget, XML sitemaps, Yoast SEO sitemap, breadcrumbs and internal link suggestions.
<a href="https://demo.tastewp.com/whp-hide-posts" title="Demo" rel="nofollow ugc">Try the Demo</a>
<h4>Features:</h4>
<ul>
<li>Hide posts on specific archives and pages (home, categories, search, tags, authors, date, blog page, etc.)</li>
<li>Hide posts from RSS Feed and REST API</li>
<li>Hide posts from XML sitemaps (WordPress core and Yoast SEO)</li>
<li>Hide posts from Yoast SEO breadcrumbs and internal link suggestions</li>
<li>Full Gutenberg Block Editor support with metabox in sidebar</li>
<li>Works with Gutenberg Query Loop and Latest Posts blocks</li>
<li>Custom Post Types support – enable hide functionality for any post type</li>
<li>WooCommerce integration – hide products on store page, category pages, and REST API</li>
<li>Bulk Edit and Quick Edit support for efficient management</li>
<li>Custom database table for optimized performance</li>
<li>Comprehensive caching for fast page loads</li>
</ul>

Hide Posts

The plugin does exactly do what I was looking for the way I expected it to work without the need to configure anything. Thank you so much! If I wasn't a software developer myself, I'd hire you! And I'd donate, but I couldn't find any hint to the usual suspects ...

Magnificent

Allows you to hide any posts on the home page, category page, search page, tags page, authors page, RSS Feed, REST API, XML sitemaps, SEO integrations …

Restrict Media Library Access vs Hide Posts