[Solved] Are all the Debian projects equal

You said near the end of this video you recommend using Debian project. As far as I know, there are quite a few distros based on Debian. I know personally of two: Ubuntu and Kali Linux. The latter is for sure built for security, but what about Ubuntu? Do all the Debian distros use reproductive builds or is it limited to the Debian project itself?

Yes there are lots of Debian derivatives.

My reasons;
Reproducible builds - Although not perfect this is our last best hope for not getting back-doors in the operating system. Debian is part of a small number of projects attempting this. Ubuntu is not.
https://reproducible-builds.org/who/

Security - Is a top priority. Fast bug fixes. A security audit team. Public disclosure for fast bug fixes. Bugs can be tracked publicly.
The reasons here;
https://www.debian.org/intro/why_debian

Packages
"Debian’s packages are divided into three main categories: Unstable, Testing, and Stable. A new package enters stable, and transfers into Testing when it has been debugged. When an official release is prepared, the current packages in Testing under further examination, and are eventually become the new Stable.

In recent years, other repositories have been officially or unofficially added, such as Experimental, Old Stable, Security, Backports ,and Update. However, users should pay most attention to the three main repositories.

The advantage of Debian’s system is that you can choose a position anywhere between two extremes: rock-solid stability, at the cost of older versions of software, or cutting edge, at the cost of less robust software and, at times, drastic changes in technology that can cripple an unwary user’s system. The choice can depend on whether you upgrade a core component, such as the Linux kernel, or a self-contained utility with its own libraries that affects nothing else when disaster strikes.

By contrast, Ubuntu derives its packages from Debian Unstable or Testing. Instead of being organized by testing status, Ubuntu’s repositories are organized by other criteria. Main contains software supported by Canonical, Universe software supported by the Ubuntu Community. Restricted contains proprietary drivers, while Multiverse holds software with copyright or legal limitations.

Another major difference is that Debian is much more dedicated to software freedom. By default, it installs only free software, and its installer even goes so far as to offer a kernel free of proprietary firmware. If you want nonfree software, you have add the Contrib and Nonfree sections to each repository.

By contrast, the distinction between free and proprietary is much less clear in Ubuntu. While Debian discourages the use of proprietary software (although allowing users to make their own choice), Ubuntu encourages users to install proprietary software in order to have a computing experience comparable to that on any commercial operating system. You can get the same experience on Debian if you are willing to work, but Debian makes clearer that you do so at the expensive of software freedom."

Kali Linux is not a secure OS… It’s built for cracking and not defending.