I guarantee you that I can find a piece of paper older than 25 years quite easily. I probably have one in my attic.
I can find you a microscope and telescope even older.
Or if we're talking electronics, electronic games and games older than 25 years.
25 years is, to be honest, pathetic in terms of longevity. I have electronic toys from my childhood that haven't been particularly looked after which still work just fine.
To be honest, I'm sitting here thinking "Only 25 years?". I have a 1960's memory chip on my desk. It's the size of a dinner plate. If I had the room-sized supercomputer that went with it, I might even be able to tell you if it's working. I see no reason for it not to as it's in perfect condition and still in the original box.
25 years is really pathetic.
And how much tech has lasted that long? A handful of things across the world.
How much is going to last 50-100 years? Almost nothing.
And there goes entire periods of history with no permanent record, of technology or data.
To give you a clue, this memory chip only has the code C630-5150-T001 on it. Find me a spec sheet. A manufacturer. Tell me what it does or how to interface with it.
It's pretty, but it's completely dead technology without spending literally tens of thousands to analyse how it works and destroying it in the process.
Now consider what's going to happen to everything else by the time they are that old. It's only another 20 years that you're asking of this C64. By then, even the generation that grew up with it and now enjoy it on emulators will have started to forget about it, and certainly how it works. You think your grandchild's generation are going to care at all, even the archivists and museum curators?