NOTE: This suggestion is for Confluence Cloud. Using Confluence Server? See the corresponding suggestion.
Status Update: March 2022
My name is Hilary and I'm a Product Manager on the Confluence team where I focus on the Confluence admin experience. Thank you for the feedback and continued discussions on this ticket, we hear you loud and clear and understand that this has been a long requested feature in our product and something that we would love to bring to market.
I am happy to announce that we are adding automation to Confluence, which could be used to bulk delete attachments across your spaces or entire site. While deleting attachments won't be included in our MVP release of automation, it's something we will certainly consider adding to the roadmap going forward. The Confluence automation Early Access Program will open up next month (April 2022) - if you're interested in automating the deletion of attachments, please give us feedback there!
Thanks again for the feedback, and if you'd like to follow up directly you're welcome to send me an email firstname.lastname@example.org
Senior Product Manager