[Cthulhu_]

Now you mention it, a stack trace with function calls and all their arguments would be really powerful. But also expensive, ideally it would have zero overhead or only have the cost if you actually look at it / want to debug it.

[kbolino]

One of the major optimizations is to pass function arguments in registers instead of on the stack. These registers might preserve their original values by the time you unwind the stack, but in many cases, probably won't. Preserving those values would lead to fewer available registers and/or more frequent register saving, which would create at least some overhead, even if you don't ever inspect it.

There are probably lots of situations where it's worth it, though.