C is still, I have to imagine, the closest thing we have to a language available for all platforms that exist today, while C++ is heavily burdened with featuritis and Rust is limited in platform support.
Rust supports everything you are likely to see in the wild outside of highly, highly specialized applications (e.g. ancient mainframes, satellites from the 80s or 90s, etc.).
For God's sake, it's becoming increasingly difficult to justify writing code that takes into account CPU endianness, because all CPUs that are likely to run your code are little endian!
99% of ARM usage is done in little endian. all android & ios phones, all embedded boards that ship with linux, etc. are always configured in little endian.
Okay, assuming you're right, how much overhead is it to consider endianness? I've never had issues with it, unless I'm implementing something fully from scratch, and that's rare in a production environment.
People that deign network protocols love love big endian.
Which means on the software side you then have to swap everything from big endian to little endian. And you need to do that at the first opportunity so their big endian crap doesn't get loose in the rest of the code.
