This is exactly the situation many employers are now experiencing. Because more vacancies generate fewer and fewer hires, they result in smaller and smaller reductions in unemployment. But large numbers of vacancies are, of course, a hallmark of tight labor markets and additional vacancies continue to strongly boost wage growth and quits.
The curve farthest to the right, labeled s=2.5, represents a situation when the separations rate is 2.5 percent, a historically high level. This rate is approximately the level seen in the middle of 2020, just after the onset of the pandemic.