pfr I'll give up my quest on this one I suppose
I should've been more careful in my initial reading of this. I assumed you meant. "What can we do to rid NetBSD of all GNU stuff", when I should've read it as: "What can I do to get rid of the GNU on my machine". In which case, it's not that quixotic of a quest. Taking @nia's list, there are replacements possible:
grep: plenty of performant replacements written in Rust on github. (not sure if they take the same switches, etc.)
gettest: purge
texinfo: purge
groff: purge (most docs already come with the plain-text and .ps versions)
cvs/rcs: ??? (only of interest to developers)
binutils: use clang tools? (ld.lld, llvm-ar, ...) ( " )
gcc: clang, pcc ( " )