Hi Ashley, yes, that is always an interesting conversation.
They're like computers, in a way. You certainly expect that they'll last three or four years, and you'd be disappointed if they don't make it that long.
But you also expect that they will need to be replaced eventually. Some of them literally stop working, because of some kind of fault. Others become obsolete, because of technology or software changes. In my time, I have had to replace several devices for both of those reasons.