Are HTTP Headers really useful?

Hi everyone, I’ve been reading about HTTP Headers and wanted to ask about their real-world effectiveness. Specifically, I’m curious about: • Content-Security-Policy • HSTS (Strict-Transport-Security) • X-Frame-Options • X-Content-Type-Options • Referrer-Policy • Permissions-Policy Are these headers genuinely useful? I’m not very experienced in this area, so I apologize if this is a basic question. Thanks in advance for your patience and advice!