I was lucky to get 2 years out of dewalt ni-cd. Hard to get dewalt to honor their warranty too. I still have one working Li and 2 older Ni-Mh. I think the Ni-Mh is the battery in the bunny that keeps going and going.
I tend to think those who have better luck may not use them like I do.
When the price of Ni-Mh is close to that of a Ni-cd, I'll buy the metals.
Have way too many 18v cordless dewalt tools to throw them away.