Jose Mortellaro

It disables the global style inlined by WordPress since WP 5.9. It also removes the duotone SVGs added after the opening body tag.
Even if you don’t use the full site editing, since WordPress 5.9 you will have an inlined style and some duotone SVGs added by the core on all the pages of your website.
The global inlined style is not enormous, but it’s also not very little. Around 5 kB added to the document may make a difference if your document is already heavy.
Moreover, why should your page have this style if you don’t need it?
Activate Disable Global Style and you will get rid of it.
<h3>How to disable the global style added by WordPress since v. 5.9</h3>
<ul>
<li>Install Disable Global Style</li>
<li>Done</li>
</ul>
No settings needed for this plugin. Just activate it and that’s it.
<h3>How to check that the global style is not inlined</h3>
<ul>
<li>Disable the plugin</li>
<li>Load a page of your website</li>
<li>Inspect elements (right-click => Inspect Elements)</li>
<li>Search for “global-style-inline-css”</li>
<li>Activate the plugin</li>
<li>Search again “global-style-inline-css”</li>
<li>If you find “global-style-inline-css” when the plugin is not active, but you don’t find it when the plugin is active, it means that it works</li>
</ul>
Clear the cache if any before to check.

Disable Global Style

I'm the author, but also a user of my own plugin. It does its job, so it deserves 5 stars.

very simple to disable the global style

It disables the global style inlined by WordPress since WP 5.9.

Sascha Huber

WP Deactivate Features lets you deactivate unneeded functions to improve your websites performance. 
Features that can be disabled: 
* Emojis 
* Comments 
* Heartbeat 
* Pingbacks 
* REST-API 
* RSS-Feed

WP Deactivate Features

WP Deactivate Features lets you deactivate unneeded functions to improve your websites performance. Features that can be disabled: * Emojis * Comments …

Disable Global Style vs WP Deactivate Features