Freemius

Kevin Amorim

This plugin allows to easily upload a CSV file with bulk pricing for simple and variable products.
The plugin dashboard page lists all existing bulk pricing lines and allows to export them to a CSV file. 
For further help while creating the CSV lines you can export both the products list and the available roles list.
Some further customization is also possible by:
<ul>
<li>Defining if we want to use roles or completely ignore them.</li>
<li>Use the total cart quantity or the quantity by specific product on bulk calculations.</li>
<li>Enable bulk pricing for guest (not logged in) users.</li>
<li>Display product total on the product page.</li>
<li>Display an additional label next to the price defining wether it includes taxes or not.</li>
<li>Hide taxes on the product page for specific roles.</li>
<li>Debug mode which displays further information.</li>
</ul>

Role Based Bulk Quantity Pricing

Use a CSV file to set bulk quantity pricing by roles, for WooCommerce.

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.

Role Based Bulk Quantity Pricing vs Restrict Media Library Access