Michael Sumner

<blockquote>
Does one thing: disables the Widget Block Editor feature.
</blockquote>
Activate this plugin to disable the Widget Block Editor functionality (added in WP version 5.8). To re-enable the widget block editor at any time, simply deactivate the plugin.
Features
<ul>
<li>Simple to use – activate and done.</li>
<li>No permanent modifications are performed.</li>
<li>There are no configuration options to worry about.</li>
<li>Easy peasy.</li>
</ul>
Why is this useful?
WordPress 5.8 was launched on July 20, 2021, and contained some enhancements to the WordPress block editor. Among those features was an introduction to WordPress’s new Widget Block Editor.
Now, why would you want to deactivate this function in the first place? You may have script conflicts that prevent you from using the widgets due to the block editor and conflicts with other plugins.
Privacy
This plugin does not collect or store any information about the user. It does not use cookies or link to any third-party websites. Thus, this plugin has no effect on the user’s privacy.

Disable Widget Block Editor

Activate this plugin to disable the Widget Block Editor feature that was added in WP v5.8.

stanxp

This plugin will disable the visual editor for selected page(s)/post(s)/custom post types. The idea behind this came after i had to keep the html intact by the tinymce editor whenever i switched back to Visual tab in the editor.

Disable Visual Editor WYSIWYG

I've added this to my list of "Essential Plugins". Doesn't need to be by default, but it makes it wonderful for having multiple admins coordinating pages and making sure people know when they can/shouldn't rely on the WYSIWYG editor.

Reduces so much pain

This plugin will disable the visual editor for selected page/post..

Disable Widget Block Editor vs Disable Visual Editor WYSIWYG