I probably wouldn't want a pet like that as cool as it sounds in theory. As painful as it is to lose a pet or anyone in my life, I already worry about what will happen to my SO or other loved ones if something happens to me first. I worry about my pets and try to make plans for the "in case" so mine have 2 sets of planned caretakers.
I know too, I wasn't that responsible as a teen and didn't think ahead like that. Even in my 20's I didn't think about it much when I acquired pets. (I'm sure some people are more mature than I was.) So, if I had acquired a cat or dog when I was 20 and it could have lived to be 55, I doubt I'd still have it today after multiple life changes, relationships, moves, etc. Just my thoughts on it.