Spam Prevention in Comments

Hoping you can help me out with a little spam prevention. I've tried adding the following code to my GeneratePress child theme functions.php to disable the comments URL/website field and to disallow html in the comments section to try and cut down on spam comments but it doesn't seem to be working. I see in /structure/comments.php there is some customization going on with the comments section, maybe that's conflicting?

Disable URL field:

add_filter('comment_form_default_fields', 'unset_url_field');
function unset_url_field($fields){
if(isset($fields['url']))
unset($fields['url']);
return $fields;
}

Disallow html

function wpb_comment_post( $incoming_comment ) {
$incoming_comment['comment_content'] = htmlspecialchars($incoming_comment['comment_content']);
$incoming_comment['comment_content'] = str_replace( "'", ''', $incoming_comment['comment_content'] );
return( $incoming_comment );
}
function wpb_comment_display( $comment_to_display ) {
$comment_to_display = str_replace( ''', "'", $comment_to_display );
return $comment_to_display;
}
add_filter( 'preprocess_comment', 'wpb_comment_post', '', 1);
add_filter( 'comment_text', 'wpb_comment_display', '', 1);
add_filter( 'comment_text_rss', 'wpb_comment_display', '', 1);
add_filter( 'comment_excerpt', 'wpb_comment_display', '', 1);
remove_filter( 'comment_text', 'make_clickable', 9 );