The whole explanation is in this line in the OP:
Although entropy must increase over time in an isolated or closed system, an open system can keep its entropy low that is, divide energy unevenly among its atoms by greatly increasing the entropy of its surroundings.
This provides pretty much the basic definition of life -- living systems are those that systematically function as entropy "refrigators", pumping entropy out of their own systems into their environment. Nothings forbids such a system in principle, so why shouldn't it happen ? Once such a system gets going, it's in its very nature to continue/propagate.
Anyone who thinks life is in contradiction with thermodynamics doesn't understand even basic thermodynamics. You have to read the entirety of the Third Law -- it applies to closed systems, and places
no direct restrictions on open systems. Living organisms -- and the whole planet -- are open systems, so do not contradict the Third Law. No contradiction, no big mystery. Yes, life is amazing, but not magical.