Remove add to cart button from products that do not have stock

file.php

//not sure what to do with this code snippet? See https://www.thathandsomebeardedguy.com/what-do-i-do-with-these-code-snippets/
add_filter( 'woocommerce_loop_add_to_cart_link', 'handsome_bearded_guy_maybe_remove_add_to_cart_button' );

function handsome_bearded_guy_maybe_remove_add_to_cart_button( $html ) {
 global $product;
 if ( 'simple' === $product->get_type() && ! $product->get_stock_quantity() ) {
  return null;
 }
 return $html;
}

My only guess would be that the parent product may actually be returning something that evaluates to true from get_stock_quantity while it is the variation that is out of stock.

might want to enable WP_DEBUG and add some logging statements to see what's what.