Salt has to be told to dissolve in water? Hydrochloric acid to fizz on concrete? Water to run downhill? Skunk scent to diffuse toward your nose? Lots of things happen spontaneously.
And we do have a fair bit of chaos in the universe.
You have answered my question. If acid remains in the container and the concrete is there, nothing happens. REACTION BEGINS ONLY WHEN THEY COME IN CONTACT WITH EACH OTHER. Here, no reaction can occur until the two react or mix. This has nothing to do with spontaneous activity.