I believe the fact nobody has been able to reduce the "reducible" complexity you point out for the past 40 years is telling. And no, the NeXT .app folder thing does not reduce it - it replaces the shared library "problem" with other problems (security and just plain malfunction) through obsolete duplicate libraries that may or may not get updated by someone other than the packager.
> First of all, note what you said: every developer.
I'm sorry, but I don't think BeOS was ever aimed at someone other than developers. It would be quite surprising if Haiku were aimed at a different public.
Again, I fail to see your problem with package management. My mother uses a Linux machine and the only contact with package managers she has is the auto-update feature - and her machine is working for 4 straight years without a full reinstall, which is more than most other OSs can say about machines that are not actively managed by someone knowledgeable. I manage dozens of Linux machines and I never experienced the package management disasters you describe.
Maybe you should get some first hand experience and, dare I say, read the manual. If you experience a significantly larger number of disasters than your peers, the problem is most likely not the tooling.