WP-CLI Uncaught Error: Class ‘WP_Upgrader_Skin’ not found

The message is caused by a plugin you are using that is not compatible with WP CLI. I suspect this plugin is the cause: https://www.ads-software.com/plugins/worker/ – deactivate it and check whether the message then disappears.

Debug (bootstrap): argv: /bin/wp plugin list --debug --path=/home/web/public_html (0.671s)
Debug (bootstrap): ABSPATH defined: /home/web/public_html/ (0.671s)
Debug (hooks): Executing hook: before_wp_load (0.671s)
Debug (context): Using context 'cli' (0.672s)
Debug (bootstrap): Begin WordPress load (0.672s)
Debug (bootstrap): wp-config.php path: /home/web/public_html/wp-config.php (0.672s)
Debug (bootstrap): Looking for UTF-8 BOM (0.673s)
Debug (bootstrap): Looking for UTF-16 (BE) BOM (0.673s)
Debug (bootstrap): Looking for UTF-16 (LE) BOM (0.673s)
Debug (hooks): Executing hook: after_wp_config_load (0.674s)
PHP Fatal error:  Uncaught Error: Class 'WP_Upgrader_Skin' not found in phar:///usr/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/UpgraderSkin.php:13
Stack trace:
#0 phar:///usr/bin/wp/vendor/composer/ClassLoader.php(571): include()
#1 phar:///usr/bin/wp/vendor/composer/ClassLoader.php(428): Composer\Autoload\includeFile()
#2 [internal function]: Composer\Autoload\ClassLoader->loadClass()
#3 [internal function]: spl_autoload_call()
#4 /home/web/public_html/wp-includes/functions.php(650): unserialize()
#5 /home/web/public_html/wp-includes/option.php(247): maybe_unserialize()
#6 /home/web/public_html/wp-includes/cron.php(1208): get_option()
#7 /home/web/public_html/wp-includes/cron.php(779): _get_cron_array()
#8 /home/web/public_html/wp-includes/cron.php(832): wp_get_scheduled_event()
#9 /home/web/public_html/wp-includes/class-wp-recovery-mode.php(99): wp_next_scheduled()
#10 /home/web/public_html/wp-settings.php(465): WP_Recovery_Mode->initialize()
#11 phar:///usr/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/Runn in phar:///usr/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/UpgraderSkin.php on line 13
Fatal error: Uncaught Error: Class 'WP_Upgrader_Skin' not found in phar:///usr/bin/wp/vendor/wp-cli/wp-cli/php/WP_CLI/UpgraderSkin.php:13

Even after deactivating the plugin, the wp-cli still displays the same error.

Has the must use plugin also been removed? According to the first error message, it can be found under /home/web/public_html/wp-content/mu-plugins/0-worker.php.

Then deactivate all plugins. Does the error still occur? If not, activate them individually until it occurs again.