Remove Core Gutenberg Blocks

disable_core_blocks.php

<?php

// Disable core WordPress Gutenberg Blocks

add_filter('allowed_block_types', 'misha_allowed_block_types');

function misha_allowed_block_types($allowed_blocks)
{
    $allowed_blocks = [];
    $block_types = WP_Block_Type_Registry::get_instance()->get_all_registered();
    $blocks = array_keys($block_types);

    foreach ($blocks as $block => $block_name) {
        if (strpos($block_name, 'core') !== 0) {
            $allowed_blocks[] = $block_name;
        }
    }
    return $allowed_blocks;
}