I don't think it is "by design". Many Debian contributors are frustrated as well by the packaging processes and tools, but it turns out that it is not that easy

I don't think it is "by design". Many Debian contributors are frustrated as well by the packaging processes and tools, but it turns out that it is not that easy to coordinate the work of thousands of people, most of whose contribute voluntarily in their free time. Debian was founded in the early 90's, developed by thousands and used by millions. It has tens of thousands of packages. You don't just migrate them to the newest packaging technology every day. Once upon a time the next big thing was Subversion. Now it is Git. What will it be next decade? It is difficult to keep up on volunteer work. I don't mean to say that you have to accept it as it is. If you don't like it, just go somewhere else. If you are motivated to help fixing stuff, that's wonderful. Just don't pretend we like to make stuff difficult for the sake of it. Disclaimer: volunteer Debian Developer, always on short time to contribute.