In real-world code, the need for generic data structures is shockingly uncommon. It really is. This requirement exaggeration comes about by people acting as language tourists, building amorphous code of uncertain purpose, where things like "I'm going to sum up a bunch of unknown objects" seems like a serious need.
For most people who find Go to be a compelling language, it excels for practical, real-world needs.
I have heterogenous priority queues where I want to push in JSON data and plain strings, I have custom iterators, concurrent data structures, default dictionaries, etc.
Seriously, look up Python's itertools and data structure modules and realize that there's a wealth of things that are useful and practical and, above all, reduce code size while preserving interface contracts and semantics. Go is completely unsatisfactory in this regard.
How do you make a custom, generic data structure without syntax overhead? I have not seen any counter proposal to this aside from "maps should be enough for everybody".
How do you avoid the noise from not having operator overloading or a similar alternative? This, again, goes unadressed.
What are the succint alternatives to functional abstractions for quickly processing collections of data?
"Just use a channel" doesn't really ring like a reasonable alternative to these questions.