I just had to do the same and decided to just add a plugin after the getKeywords Method of the page config which returns a null string. works great

di.xml:

    <?xml version="1.0"?>
    <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
        <type name="Magento\Framework\View\Page\Config">
            <plugin name="removeMetaKeywords" type="Vendor\Module\Plugin\PageConfig\RemoveMetaKeywords" sortOrder="9999"/>
        </type>
    </config>

Plugin Class:

    <?php
    declare(strict_types = 1);
    namespace Vendor\Module\Plugin\PageConfig;
    
    class RemoveMetaKeywords
    {
        public function afterGetKeywords($subject, string $return)
        {
            return (string)null;
        }
    }