Sonatype allows "io.github.<username>" as a valid groupId and has a process to verify ownership. I am sure other providers like GitLab can work on this.
The problem with this argument against, is that it reinforces the point it is arguing against: If a contributor cannot afford the $20/year to publish for a single 12-month period, then they are already a risk - someone could buy their account off them.
A small bar of $20/year is also enough to completely cut-down on contributors who sign up with the intention of publishing malicious packages: they have to pay $20/year for each malicious package they want to publish!
Why should someone need a credit card to contribute to open source? Why should they need to understand DNS?
Heck domain names are ephemeral, forget a deadline by a day and they are snatched up my squatters. They don't provide any extra guarantees. Do we really think a domain requirement is going to stop state level actors that are already stealing 2FA package publishing tokens from major software orgs?
> Do we really think a domain requirement is going to stop state level actors that are already stealing 2FA package publishing tokens from major software orgs?
Is that your target? Because if so, then nothing will stop them.