More public servants claim they are redundant

I don't get the "redundancy" passion of governments. 
Big payouts help rid the ranks of deadwood, maybe tired and burntout public servants. 
Maybe they just needed a break and finding an area of passion where their experience and commitment could make a difference. If they really want to enjoy early retirement and have areas of interest to move into well good for them. But how many still have so much to offer, if the effort was made to find where they will make the most difference.
Colleagues, friends, mentors, confidants are lost to save money. Graduates are cheaper.
How many public servants made redundant will come back to fill the gap their departure left in the same department?