BE isn’t technically dead buts it’s practically dead for almost all projects. You can static_assert byte order and then never think about BE ever again.

All of my custom network serialization formats use LE because there’s literally no reason to use BE for network byte order. It’s pure legacy cruft.

...Until you find yourself having to workaround legacy code to support some weird target that does still use BE. Speaking from experience (tbf usually lower level than anything actually networked, more like RS485 and friends).