We've always rehomed older cats. We had Copper, who we got at 14 because her owner had a baby and decided not to keep her (Copper not the baby)
. Copper died a week short of her 18th birthday. Homer was 10+ when we got him from the shelter; he was FIV+ and very timid; had been a stray a long time; he had two good years with us before he had to be put to sleep when his kidneys failed.
Cassius came to us 8 years ago aged between 6 and 10; he's had a chequered veterinary history and now has cancer of the bones in his face. At the moment, he's still in great form and enjoying the sunshine here. I'm going to miss him hugely.
Felix is 7 and the baby (in all sorts of ways), has chronic cat flu contracted as a kitten but is a gem of a boy.
I love our cats and certainly wouldn't be without them.