2 Answers
I think that’s now an on-creation-only setting.
I had to untick "Enforce public access prevention on this bucket" at bucket creation (step 4, "Choose how to control access to objects"), and even then I had to manually add allUsers
with both of the roles Storage Legacy Bucket Reader
and Storage Legacy Object Reader
to make the public file (sorry, "object") link in that public bucket work.
I guess it’s a good thing that Google makes it hard to accidentally make a bucket public?
Videos re outdated with respect to the changes in the GCP options.