Nhat Huynh Van

<blockquote>
It’s hard to change if you love something!
</blockquote>
I’ve been using the original/classic editor for over 10 years now and the experience has always been 100% smooth and the original Visual Editor was awesome. 
I like to keep that to myself and I’m sure there are some people like me who like the classic, easy to use and simple thing.
This plugin disables the new Gutenberg Editor (Block Editor) and replaces it with the Classic Editor. 
The Disable Gutenberg plugin restores the classic (original) WordPress editor and the “Edit Post” screen.
Features
<ul>
<li>Classic Editor</li>
<li>Disable Block Widgets and restore Classic Widgets</li>
<li>Enable/disable frontend Gutenberg stylesheet</li>
</ul>
<blockquote>
Works same as Classic Editor plugin, but lightweight, simple and super fast
</blockquote>
Easy to Use
<ul>
<li>Super simple</li>
<li>Clean, secure code</li>
<li>Built with the WordPress API</li>
<li>Lightweight, fast and flexible</li>
<li>Works great with other WordPress plugins</li>
<li>Focused on flexibility, performance, and security</li>
</ul>

Relive Classic

Plugin Relive Classic is help you use editor, widgets in classic style and disable Gutenberg.

Md Khorshed Alam

The Block Editor Disabler Plugin allows you to easily disable the Gutenberg block editor on your WordPress site. 
With this plugin, you can choose to disable the editor for specific pages, all pages, or even all posts, giving you complete control over your editing experience.
<h3>Features</h3>
<ul>
<li>Giving you complete control over your editing experience.</li>
<li>Show all control on Block Editor Settings admin menu page.</li>
</ul>
<h3>Video Tutorial</h3>
Include Soon!

Block Editor Disabler

This plugin for disable gutenberg editor for specific role.

Relive Classic vs Block Editor Disabler