I find the refrigerator and McDonald's bathroom stall both to be a fairly straightforward metaphysical deduction from the generation of life on this planet and its consequent blossoming of civilization. Both of those things are byproducts that support the functional needs of humans which are the ultimate result of evolutionary dynamics in carbon based life forms found on the planet.
These things which are crazy complex (which you did not pick particularly complex examples of, better examples might be quantum computers or nuclear reactors, but that's ok) are a natural result of the process that evolution kicked off (this is the accident that you refer to) that allowed people to be a thing, which, when they do their thing results in astounding advancements that necessitate complex designs to fulfill their function. I personally don't believe there needs to be a better reason to explain why we have refrigerators, mcdonald's bathroom stalls, quantum computers, and nuclear reactors other than "because we can". That is to say, once humans became capable of inventing those things, it was inevitable that they would proliferate.