You sound as if "my asserts will all always be run via NDEBUG" makes perfect sense and not the exact opposite of what you've expanded it to
> Its common practice
not really, no
post ++11 cpp has been moving away from preprocessor (pedagogically and culturally), so "let's force-undefine NDEBUG" trick isn't at the top of most people's minds
If you want to use asserts, you need to control the definition of NDEBUG. You either do this with your build system (common), or manually (slightly less common). This is literally <assert.h> 101
The preprocessor is widely used for a variety of things when its necessary, including #includes and #defines, because there's literally no other mechanism for this. Its bizarre to say that nobody controls the definition status of NDEBUG because people don't use the preprocessor