You obviously never tried to compile C++ with that.
I did, on an 68030 with 7MB (4MB on the A2630,2MB Z2 and 1MB CHIP).
It might be somewhat useable with today's resources (NG or UAE) ....
.... for compiling and running........
Who in their right mind compiles anything bigger than hello world on 68k silicon today though?

SAS/C 7 ran fine under MorphOS on my PowerBook last time I tried (circa 2013) but obviously there are far better solutions like GCC.
It's a shame vbcc was never given C++ support IMHO though.