> I know why they are useful. I am arguing they are waste of time for effort involved.

Not being reproducible is a bug.

There is no reason for a build to not be reproducible, but somehow we let the built binaries become infested with timestamps, login names and file system paths. We recently moved to reproducible builds at work, and discovered that our login names and local home directory paths were being shipped in every release. No one was was very happy about leaking PPI like that.

You may not consider it worth the effort, but you aren't the one putting in the effort so I'm not sure why that matters to you. It is very much worth the effort to those people doing the work. Debian is a do-orcracy and so the people doing the work get to make the decisions.

A hardware key does not help if the developer's machine is compromised, as there is no change to understand what is signed anymore, or do you think the hardware key will show all the source code on its little display before signing?

With reproducible builds, you do not need to trust that the system that build the binary was not compromised, because this would be detected immediately.

Source compromises are still an issue, but there is a much bigger change that they are detected. Also if there is a compromise, reproducible builds allow you to later track it to the source. For an infected binary it is much more difficult to understand how it got there and what else might be compromised.