Is it able to delete all voice messages from WhatsApp in iPhone?

Voice messages spent me 10GB+ storage every years and its definitely useless.

The "Manage storage" in Settings manage medias but not voice message, the top banner said "Used" storage is also only counting Whatsapp media without voice message. So, while using icloud backup, it spent a lot of cloud storage to backup useless data.

I searched everywhere for it but cannot get an answer including asked whatsapp support team.