IMO that 99+% of the work done upstream is the cross-distro collaboration

In my mind, when I look at the totality of work that went into producing the open source distro in front of me that I'm using, I see 99+% of that work as the code that is upstream, and already shared, and thus collaborated between all the distros. I think that this complaint about lack of collaboration is failing to acknowledge the overwhelming majority of collaboration that is already in place in the form of shared upstreams.

And when I look at the bigger differences, I don't see a wasted duplication of effort, but an organic competition of options/traits in what is effectively a gene-pool of overall system defining ideas.

Consider any other craft, like say, people who build guitars. Is there a lot of duplicated effort, and wouldn't things be more efficient if there were just one assembly-line making a bunch of guitars that all satisfy at least 95% of the needs of all the existing users? Sure, maybe that would be more efficient, but it would also be a really boring solution, versus one which supports lots of independent craftspeople all getting the fun of building their own slightly different guitars.