This is similar to buying a DVD. You don't buy the right to the video playing on your TV; only the right to play it on your TV from this exact physical disc. If the disc breaks, you have to buy it again.
It is possible for your disk and backups to break, or to be stolen, etc. But it’s just an unfortunate thing that can happen to anything you own. It’s different from the corporation taking away the rights of millions of people just because a licence ran out.