
(Again just tagging on to the end.) I have had 3 personal friends who literally dropped dead, no warning beforehand and none were accidents. One was 47, one in her 40s, one was 58. Not old. When my grandparents lost their last dog they said they couldn't get another as it may outlive them. Both my mother and I said that if they got a dog, we would give it a home if ever they couldn't, but they still didn't feel able to. They spent 20 YEARS without a dog, and they were miserable. I remember getting my first ever puppy and my grandfather was admiring him and talking to him. He said something along the lines of "You're so beautiful and lovely but one day you will die as well, just like our dog did." I don't ever want to be part of anyone feeling that way. When my widowed and disabled mother in law lost her elderly dog we gave her one of our Cavaliers. When he died we got her a Labrador from the council stray kennels. When she (the Lab) died my MIL was in her 80s so we let two of our oldest dogs live with her and we did everything, so she had the company of dogs but zero responsibility. When MIL died the dogs became ours again.
A few years ago I was approached by a man in his 70s enquiring about a pup of my large, energetic breed. He had dog experience but not of such specialist breeds/high energy. But he'd done his research and he said straight up that he wanted a breeder who could be trusted to have the dog back should anything happen to him, and I agreed. He's now competing in obedience and rally and tricks and has got a second dog from another breeder, friend of mine, under the same condition. If his dog comes back one day, it will be a well socialised and VERY well trained dog indeed. I'm happy to take that risk.
I've also sold my high energy breed to four disabled people who wanted to train their own assistance dog. One was experienced, two were very experienced, and one had very little experience but spent 3 years researching, meeting breeders etc. All four have so far done amazingly well and the first qualified as an assistance dog. (The other 3 are still puppies.)
If you breed you have to be prepared to take a dog back at any time for any reason whatsoever. If you pick your buyers carefully it only tends to happen when something really out of the ordinary and unexpected happens. Being 70 doesn't guarantee that you will die before the dog and won't be fit enough to cope with it, but neither does being 25 guarantee that you won't. None of us know the future so we can only judge in the now, going with the info and gut feelings we have -plus contracts stating you will agree to have a dog back at any time.