1 atom of Cesium is .26nm (largest). 2nm is at the granularity level of 8 Cesium atoms! For Silicon .11) we are talking about transistors made of 18 atoms (roughly?)?

My question is, do they factor in a significant transisyor failure rate and silently reroute or something or are things actually stable enough to survive years of real world usage without transistor failure becoming an issue?