My sister had one that made it to 22, a Siamese-Tabby mix. She lost her sight, but she just meowed really loud to “echolocate” herself around the house.
I had never heard of a cat doing that. Isn’t that seriously cool?
We have an old lady about to turn 21. She’s a little deaf now, & when she wants us to do something she yells...LOUD. Sometimes she comes up behind me very quietly & then cuts loose. It’s a miracle I haven’t left a hole in the ceiling.