Alex Kuimov

SP Disable Block Editor is a WordPress plugin which can disable Gutenberg Editor

Disable Gutenberg (SP Disable Block Editor)

SP Disable Block Editor is a WordPress plugin which can disable Gutenberg Editor

Sumit Singh

Classic Widgets with Block-based Widgets allows you to use both widgets screens at the same time. 
Sometimes, you need to use the classic widget screen for some of the widgets without permanently disabling the block-based widgets. With this plugin, you can access the Classic Widgets screen in <code>Appearance > Classic Widgets</code> and the block-based screen at the usual place in <code>Appearance > Widgets</code>.
NOTE:- 
This plugin uses WordPress filters to create a new classic widget screen. That means it will work as long as WordPress supports the Classic Widgets screen.
<h4>Links</h4>
<ul>
<li><a href="https://github.com/5um17/classic-widgets-with-block-based-widgets" rel="nofollow ugc">GitHub repository</a></li>
</ul>

Classic Widgets with Block-based Widgets

Restore the classic widgets screen as a new menu item without replacing new block-based widgets.

Disable Gutenberg (SP Disable Block Editor) vs Classic Widgets with Block-based Widgets