mdd – and your point is? Medrabanan aveiros are still aveiros. And in chazal’s time, most reshuos were also derabanan, except places like Mechuzah, and yet they still were mevatel the mitzvos.
Also, I’m not so sure that mitzvos hatluyos baaretz are still derabanan nowadays; it’s possible that the majority of Halachik Jews are actually in eretz yisroel, as most censuses take into account reform and conservative “gerim” and the products of intermarriages with patrilineal descent, of which there are a ton.