How biotics work

TL;DW: Space Magic™

I think it's best to assume that Element Zero is a merely another mysterious naturally occurring substance distinct from Dark Matter. If you  start trying to rationalise Biotics and real work physics I think you'd drive yourself mad and end up ruining the allure because it's our non-understanding and otherworldly-ness which makes them cool and unravelling the mystery and mystique would ruin Clark's Third Law by making magic mundane. Tech Powers don't have quite the same allure because they are more grounded in observable real world physics and are closer to the mundane than unexplainable space magic.

On the subject of Dark Matter... who knows there may be different kinds of Dark Matter substances which don't reflect light on the visible spectrum for a variety of different reasons I guess we might live to find out one day. Maybe element zero is one such substance and there are others like it which might lead to more powerful or efficient biotics or something else entirely. I had a theory that if there are natives of Andromeda hundreds of thousands of years more advanced than us they might have moved on from Element Zero to something more powerful or more commonplace throughout the galaxy for their biotics and space travel needs.