In CheckoutWC's Delivery method, hide the Shipping option completely when at least one product in the cart is assigned to a specific category.

hide-shipping-from-delivery-methods-basesd-on-product-category.php

<?php
/*
* In CheckoutWC's Delivery method, hide the Shipping option completely when at least
* one product in the cart is assigned to a specific category.
*
* @author Obi Juan <hola@obijuan.dev>
* @link https://obijuan.dev
*/

/*
* Check if a product in the cart belongs to a specific category.
* 
* @param string $category_slug The slug of the category.
* @return boolean True if at least one product in the cart belongs to the category, false otherwise.
*/
function is_product_of_category_in_cart( $category_slug ) {
    // Check if the cart exists and is not empty
    if ( WC()->cart && !WC()->cart->is_empty() ) {
        // Loop through all cart items
        foreach ( WC()->cart->get_cart() as $cart_item_key => $cart_item ) {
            // Get the product object from the cart item
            $product = $cart_item['data'];
            
	    /*
	    * Add support for variable products.
	    * Variations in variable products do not have categories.
	    * So, we need to identify if we are checking a variation or a simple product.
	    * If it is a variation, then get the parent product ID and check its category.
	    *
	    * @contributor Wojtek Hoch
	    */

	    // Determine the ID to check based on product type!
            if ($product->get_type() == 'variation') {
                // For variations, get the parent product's ID!
                $checked_product_id = $product->get_parent_id();
            } else {
                // For simple products, get the product's own ID!
                $checked_product_id = $product->get_id();
            }
		
            // Check if product belongs to the specified category
            if ( has_term( $category_slug, 'product_cat', $product->get_id() ) ) {
                // If the product is in the specified category, return true
                return true;
            }
        }
    }
    // If no product in the specified category is found in the cart, return false
    return false;
}

/*
* Implementation.
*
* @filter cfw_local_pickup_disable_shipping_option
* @$category The category slug. E.g. "Cat 1" > "cat-1".
* @return boolean to either enable or disable the Shipping option.
*/
add_filter('cfw_local_pickup_disable_shipping_option', function(){
  
    $category = 'cat-1'; // Category slug.
	
    return is_product_of_category_in_cart($category); // True or False.
	
});