When's the last time you came across something that you could disassemble and could then reassemble into two things identical to the first thing you disassembled?
It is natural to suspect that foundational axioms are somewhere flawed.
One thing worth pointing out is that our universe operates on the integers rather than the real numbers, and the Banach-Tarski requires operating on the reals.
Is that known? It's an appealing idea, but bearing in mind that general relativity is very resistant to quantisation, I'm not sure I'd be comfortable to declare it as fact.
It is natural to suspect that foundational axioms are somewhere flawed.