I could’ve sworn I downloaded a purchase from Bandcamp on my iPhone very recently (within the past 3 months) without encountering the refusal depicted above.
How to Download Bandcamp Purchases on iPhone
Demonstrating how to circumvent the new “iPhones do not support direct downloading of music” page with a single Siri Shortcut from the official gallery.
Here’s an iCloud share link of the official “Download File” Siri Shortcut if you absolutely cannot be bothered to look it up: https://www.icloud.com/shortcuts/e35024b543fa4c5f86e6fc119d0a47ee
The VLC app I mentioned: https://apps.apple.com/us/app/vlc-for-mobile/id650377962
And the most important link of them all! https://hjkl-8901.bandcamp.com/album/memecore-megamixxx-live-at-909-worldwide-untitled