Gyfycat has also been running for 8 years, Imgur for 14. I'm talking only about the longevity of a service running. I don't think people are expecting any instance to run for that amount of time, though its obviously too early to tell.
Clearly these large centralized services eventually decay away due to power hungry individuals within, but it takes some time.
I'm not sure if people are going to read this as I'm pro-centralized services, because I'm not, I'm just making statements.