The original problem with reporting bugs to a mailing list was mails for many bugs were mixed and you couldn't easily get the state of individual bugs. Debbugs, by automatically creating a new mailing list for individual bugs, does solve this problem admirably.

The new problem is that new people hate emails. I think the merit of this problem is debatable.

Mailing lists have had threads for decades.

You can subscribe to individual bugs in Debbugs, you can't subscribe to threads. Threads also don't have short ID (bug 123456) and don't have metadata like whether the bug is closed.

Broken email clients and careless people break those all the time though...

In the long run, everyone who tolerates email is dead.

But do they die before everything else?