[bluescrn]

People will still be able to play Super Mario Bros, even though the last NES will be long gone. Code of any real value will be preserved by enthusiasts, and be run via emulation or ported to modern systems.

Meanwhile, most of todays blockchains will be dead. No nodes left to sync with. Maybe the blockchain concept will live on in a new form, but even now, there seem to be dying blockchains that are very difficult to connect to and use (e.g. Dogecoin, at least before the recent price surge)

I guess a real threat to all historical code would be the end of open computing, and the requirement for any code run anywhere to be signed and censored by a megacorporation. Something we're getting worryingly close to. But in that world, most of today's blockchains will quickly die, too.