Stop WordPress Serving Its Logo as favicon.ico
When no Site Icon is set, WordPress answers /favicon.ico with its own logo. This returns a plain 404 instead, so your tab never shows the WordPress logo.
Snippet Library
Disable Features snippets for WordPress
Snippets that switch off WordPress features you do not use: comments, the block editor, RSS feeds, automatic updates, attachment pages and more. One snippet per feature, so you turn off exactly what you want and nothing else.