Half a century???I have 2 cars and a bedroom set older that that....and I myself exceed that by another quarter of a century....meaningless.
Be assured more could be added, but the point here is that no matter how manifestly and extensively corrupt and fractured Rome has and can become, then RCs seem to imagine a unified church always looking to an infallible supreme head in Rome (unseen in Scripture), and a all-holy church in Mary from which Biblical separation (2Co. 6:14-18) could never be compelled, and mo matter how long it remains with no successor or uncertainty as to one, then this is still defined as unbroken succession.