I don't think myself or any other Go devs I have worked with have once thought about allocation cost when using slice operations. This may be something super common for C/C++ devs but the big adopters of Go are Python and Java converts where we just don't pay attention to this stuff and after a decade or more of writing this kind of code were not going to suddenly start thinking in terms of memory allocation cost.

I think this is one of those mistakes in the language that exist because early-on Go could have been a true systems language but it's been adopted by a large number of devs more as an infra and high-level automation language where correctness is more important than performance.