Go was built as a language to make communicating sequential processes[1] first-class citizens. Thus the ubiquity of channels and goroutines. No locks, no condition variables, no callbacks[2]. Writing a bunch of code using locks and callbacks in Go goes against the grain of the language.

[1]https://www.cs.cmu.edu/~crary/819-f09/Hoare78.pdf

[2]https://www.youtube.com/watch?v=f6kdp27TYZs