yes this is obvious because during place and route, the hold time (time before which the data remains to be valid after the arrival of the clock pulse) voilations can be matched and changes can be made to the specifics.routing is imporant as it determines the wire length and which component to which floor has to connected.
Place and route is very important as it plays a very imporant role in determining the excat place where the component has to placed during the post synthesis procedure. so depending on the place where the components are placed the hold time violations can be avoided.
with regards,