The following code will remove add to cart form from single product on simple product type but will display the stock information:
// Single products (Simple): remove add to cart button and keep stock info
add_action( 'woocommerce_single_product_summary', 'remove_simple_product_add_to_cart_button', 1 );
function remove_simple_product_add_to_cart_button() {
global $product;
// For simple products type
if( $product->is_type( 'simple' ) && $product->is_purchasable() ) {
remove_action( 'woocommerce_single_product_summary', 'woocommerce_template_single_add_to_cart', 30 );
add_action( 'woocommerce_single_product_summary', 'show_stock_info', 30 );
}
}
// Function that stock info
function show_stock_info() {
global $product;
echo wc_get_stock_html( $product );
}
Code goes in function.php file of your active child theme (active theme). tested and works.